Trying to install some Python packages on a Pi 5 and PyPi search turned up nothing.
Found the following Git Hub issue. Apparently PyPi web site has been hit by bots sending too many requests and has caused two outages. PyPi shut down any access except by a browser to try and protect their web site.
So if you cannot find packages via PyPi, his is probably the reason. Manual install for Thonny is the only option.
Cheers
Jim
EDIT: Found the PyPi search still works on a Windows PC with Thonny installed, it seems only Thonny on the Pi OS that is affected.