Error adding to github?

Question

git

Hello, I can not add the project to the github.
When I write on the command line 

git remote add origin https://github.com/Almazq/twotest.git

Mistake :

error:remote origin already exists

And then I write

git push -u origin main

then you get this error

This application requires one of the following of the .NET Framework: .NETFramework,version=v4.6.1

i downloaded 3 versions not working