This app package's publisher certificate could not be verified

[hosamyousof]

I would like to publish outside the store. I created a .pfx using openssl and run the command

flutter pub run msix:publish

After publish is done successfully I opened the *.appinstaller file to install the app but I got the following message.

How can I avoid installing the certificate manually on clients computers and just let them install our app from the *.appinstaller or *.msix file directly without extra steps.