how to disable all wp updates - ever

Hello,

since automatic updates sometimes break websites, I would like to disactivate all updates and schedule manually updates once or twice a year.

I found codes suggestions for this and I would like to double check with you which should I use:

define( 'AUTOMATIC_UPDATER_DISABLED', true );

Is this the correct line? Should I just add it or should I change an existing line to this?

Thanks!