Link guest account to battlenet

Hello,
I play Diablo immortal as a guest with 2 characters level Paragon 212 and 329.
I would like to link this guest account with my battle-net account but I read some time ago that I would lose my progress and of course I don’t want to start all over again.
Is there a method to do this?
thanks in advance

You would not lose progress when linking your guest account to Battle.net.