Self contained exe does not execute on computer without .NET Core 3.1

Question

I have a self contained exe and want to run it on Windows. The target Framework is netcoreapp3.1, target runtime win-x64 and the "produce single file", as well as enable RradyToRun checkboxes are checked. Does anybody have an idea, what the reason could be. I dont want to install .NET Core on the client computer, because the self contained method would work better for my purposes.
Have a nice day everyone!

Answer 1

Younes Abdo read my question correctly! It says self contained....found the error a file was not found that I had on my pc

Answer 2

congratulations