Initially I used pip install requests within VS. The request came back, all requirements satisfied. I restarted VS with a new terminal and tried pip install requests again. This time it installed requests and then everything worked fine.
I have never used Visual Studio but from your question, it seems to be a Visual Studio environment issue.
So I google "visual studio pip install python" and I got this url,
Hope this help.
I had similar issues myself when I was trying out VS and for me, it was as explained in the link above - my VS and Jupyter were using different Python environments.
the missing package was installed in the Jupyter used env but not in the VS env