You can try doing an in-place conversion, here’s a guide and the official documentation, remember to BACKUP and TEST your BACKUP at least twice, if things don’t go well, you’ll be able to fall back.
If you want to avoid all the setup headache, just reinstall with btrfs by default (I suggest Fedora Silverblue or openSUSE Tumbleweed for that) of course you’ll still have to backup, just your data though, to be restored on the new system