C# Solution with Web and GUI projects

I am trying to build an system in C# for all modules which has a both a web site and a GUI interface. I have created two projects in the same solution. The two modules will need to talk to each. That is why I am putting them together. Maybe it is not necessary for them to be in the same solution but both need to run at the same time during testing and deployment. Presently when have compiled both modules but they are also using Entity Framework core. I have just started the web part and it cannot add the first migration. It complains that

Severity Code Description Project File Line Suppression State Error Project '..\opencreditfederation2_23_web\opencreditfederation2_23_web.csproj' targets 'netcoreapp3.1'. It cannot be referenced by a project that targets '.NETFramework,Version=v4.7.2'. opencreditfederation2_23

Now when I try to get these things matched I am stuck because the web application only offers versions of netcoreapp and the GUI app only offers .NETFramework items. Is there a way round this I should I been taking a different approach altogether?

When I try to match them up this is what I see: enter image description here