I’ve found the following to be helpful in WSL2:
sudo ln -s /usr/local/bin/xdg-open /usr/bin/wslview
Doing this will enable flyctl to launch your browser, and when launched this way, fly login should work without any need to copy/paste.
Adding the following to your .bash_aliases file will enable aliases to work:
export FLYCTL_INSTALL="/home/totti/.fly"
export PATH="$FLYCTL_INSTALL/bin:$PATH"
This change will take effect the next time you open a WSL terminal window.