.NET Build Target Issues

[Cojack622]

I played around a bit with Coqui on .NET core 3.1 about a year ago, and had no issues. Now I'm coming back and I'm having issues building. When I look at the .csproj and other files it seems the only build targets are for .NET 2/2.1/5.0/6.0. Is this new? Due to other dependencies I would prefer to use 3.1 if I could. Would that still be possible? Thank you