With no USB-C port to connect it to a computer, the Apple TV 4K falls firmly into the category of “irksome products which Apple doesn’t want you to mess with”. However, although it is easier to get your own apps onto its older brother the Apple TV 4, it’s still possible to sign and sideload apps on the 4K.
The first thing to note is thatif you are an Apple TV 4 user, you don’t need to do this.The process is pretty involved (at least the first time through), and though it will work perfectly well on the Apple TV 4, there is simply no point when you’re able to just use Cydia Impactor in a fraction of the time. To do so,followSteps 1-6of our other guide, replacing any references to LiberTV with your chosen app to sideload.

Apple TV 4K users, read on.
Prerequisites
The following prerequisite steps only have to be performedonce. Once you’re all set up you’ll never need to repeat them. If you’ve followed these steps before and sideloaded an app already you canjump ahead toHow to sign an app.
Before beginning, you must have:
1)A Mac computer, a Hackintosh, or a computer running macOS in a virtual machine.
2)Xcode, which you candownload free from the Mac App Store.
3)TheiOS App Signer application, available free from the official website.
4)Registered your Apple ID as a free developer account, which you cando very quickly on the Apple Developer portal.
5)Added your Apple ID in Xcode’s Preferences, ready to sign apps with.

6)Paired your computer with your Apple TV 4K so you can connect to it in Xcode. This is easily done byfollowing Apple’s guide on the topic.
How to sign an app
If you know your app is signed already and you just want to sideload it to your Apple TV 4K, you canskip ahead toHow to sideload an app. Examples of this scenario include saved apps which you’ve previously signed with iOS App Signer and just need to push over to your device again, and apps pre-signed by someone else with a valid certificate that you wish to use.
If you don’t know what that means, or don’t know for sure that your app is signed, you shouldassume the app is not signed, and follow the instructions in this section.

The first step will be to create a certificate and provisioning profile to sign the app with. Readers with apaiddeveloper account can create these on theApple developer site, underCertificates, Identifiers & Profiles. However, this is fiddly, and readers with a free developer account can’t do it all. For that reason, I recommend using the following method, which I find much easier:
1)LaunchXcode.
UnderXcode, Preferences, Accounts, check your Apple ID is added. This is to sign our apps with. If it isn’t, hit+to add an account, selectApple ID, and then sign in.
2)Now, in the menu bar selectFile,New Project, tvOS, Single View App.

3)Now enter the project details. TheProduct Nameshould normally be the name of the app you want to sideload, for exampleKodi. TheOrganisation Namecould be literally anything. TheOrganisation Identifieris normallycom.followed by some personal string you may use for all your apps, for examplecom.idownloadblog.
ABundle Identifierwill be generated automatically from those two fields. In the example I gave above, my bundle identifier would becom.idownloadblog.kodi. Yours will be different. TheTeamshould be the Apple ID you added inStep 1)above.

4)Once the project is open, configure it as shown below. Make sure to select yourspecificApple TV 4K unit in the top-left, not a generic one. It must be connected to your computer via the same Wi-Fi network to do this.
TheIdentityfields should be populated automatically with the information fromStep 3). TheSigningfieldsmusthave your Apple ID selected, and showno errors. Select your Apple TV 4K’s current firmware version underDeployment Target.
As you do this Xcode should create a provisioning profile and certificate automatically for your app/device, which you’re able to see listed in theSigningsection above.
You may now quit Xcode.
5)LaunchiOS App Signer. Drag the app you want to sign into theInput Filefield.
UnderSigning Certificate, select the Apple ID which you use in Xcode (fromStep 1)). ForProvisioning Profile, select the profile which Xcode generated automatically for you. It will probably have theBundle Identifierwhich was created with the Xcode project inStep 3), for example,com.idownloadblog.kodi.
The other fields can be ignored. HitStartand save the now-signed app to your Desktop.
If you will need to sideload this app again in future, keep it saved on your computer. This will avoid repeating some of the guide next time.
6)RepeatSteps 2)-5)for any other app(s) which you want to sideload. Remember to change the details in the Xcode project and iOS App Signer each time, to match the app, Apple ID, and Apple TV unit you are using.
You are now ready to sideload the app(s) to your Apple TV 4K.
How to sideload an app
1)Once you have your signed app(s) ready, launch Xcode, and selectWindow, Devices and Simulatorsfrom the menu bar.
verify your Apple TV 4K is connected and highlighted in the sidebar.
2)Click the+button to add an app. Select your signed app(s)from the Desktop (or wherever you saved them) to sideload them to your Apple TV 4K.
3)The app(s) should now appear on your Apple TV home screen. Quit Xcode, and enjoy your sideloaded apps on your Apple TV 4K.
Additional information
If you have a free Apple developer account (and aren’t jailbroken) you will have to sideload your app(s) again every 7 days. If you have a paid account, it/they will last for a year.
In future, skip thePrerequisitessection. To sideload new unsigned apps, follow the sectionsHow to sign an appandHow to sideload an appagain. To sideload previously signed apps which you’ve already created an Xcode project and signing certificate for, followHow to sideload an apponly.
If you retain your signed app(s) at the end ofStep 5)in the sectionHow to sign an app, you can resign them easily using iOS App Signer. Just drop them in and use theRe-Sign onlyoption, then push them across as detailed inHow to sideload an app.
Whew! The process isn’t actually as bad as it looks; many steps can be skipped after the first time, and others become second nature.
Problems? Let me know if you’re stuck via the comments section and I’ll try to help out.