Create a copy before you need it
Open Watchlist and choose Create backup. Copy all the generated text, including its opening and closing braces, into a note or document you control. The text identifies supported saved titles and valid checkpoints. It does not include movies, passwords or an earlier website's account history.
Merge without replacing existing checkpoints
In the receiving browser, paste the complete supported backup into Restore backup and choose Merge backup. Recognized saved titles are added without creating duplicates. Existing valid checkpoints in the receiving browser are kept rather than overwritten by the incoming copy. Read the feedback and inspect the resulting list before discarding any copy you keep.
When an import is rejected
Check that you copied the complete MyFlixerz2 backup and did not add surrounding commentary. Other brands' exports and arbitrary lists of title names are not the same format. A malformed or unsupported backup is rejected instead of being treated as an instruction to replace your data. If you only have names from an old service, find those productions through search and save them individually.
A local list needs a local explanation
Different browsers, profiles and domains can have separate storage. This backup workflow is deliberate transfer, not automatic cloud synchronization. Keep a recent copy when changing devices, and avoid clearing browser data until you understand what it will remove.