.NET location: Not found

I have followed the Ubuntu guide on the MonoGame website. Project builds correctly but the build will not start. It says:
Architecture: x64
App host version: 9.0.4
.NET location: Not found
Process finished with exit code 131.

My dotnet version is 9.0.4. I have installed mgcb dotnet tool, it supports 9.0 framework. Not sure what the problem is.

I am using PopOs.