i want to upgrade to v 12 and i already have v 11.45
if you are sure about it, change the branch
I suggest you setup a fresh server with the same database, and experiment. You’ll need to change the branch using:
bench switch-to-branch develop
Also please note that v12 is not STABLE. Hence the question of upgrading should be asked when v12 is actually released into master. Never ever risk your production servers.