How to Side-load onto another Windows machine with a Self-signed .NET MAUI app?

I created an installation package with MSIX out of a .NET MAUI Windows app and a self-signed certificate, using a PFX file.

When I try installing it on another Windows 10 machine, I get the following message: "This app package’s publisher certificate could not be verified. Contact your system administrator or the app developer to obtain a new app package with verified certificates. The root certificate and all immediate certificates of the signature in the app package must be verified (0x800B010A)". The deployment directory has MyApp.msix and MyApp.cer in it. On my development machine it is no problem to install using the MSIX file.

How do I use these files to install onto another machine that did not create the certificate?

I found the answer in this video by Gerald Versluis: Create a .NET MAUI Windows MSIX to Sideload Or Publish to the Microsoft Store

I needed to follow these steps:

1. Open the Certificate, MyApp.cer, by double-clicking.
2. Click on Install Certificate
3. In the Certificate Import Wizard window,
   1. Select Local Machine and click Next
   2. Select Place all certificates in the following store
   3. Browse and select Trusted Root Certification Authorities
   4. Click Next and take defaults. After this you should see a pop-up stating that "The import was successful." You now can proceed to side-load install the .NET MAUI app.

This worked for me. There might be minor variations that work as well.