Create a copy before changing browsers
In My List, choose Create backup. Copy the complete text into a file or note you keep privately. The backup includes your saved title identifiers and valid episode checkpoints. It does not contain movie files, another service’s account or its playback history.
Merge rather than replace
Open My List in the destination browser, paste the full backup into Restore backup and select Merge backup. Existing saved titles stay in place. If that browser already has a checkpoint for a series, its current checkpoint is kept rather than overwritten by an older copy.
If a restore fails
Make sure you copied the beginning and end of the text. The page rejects unreadable or unsupported backup formats and reports unavailable entries. Do not add a title name into the text by hand; save it from its poster instead. Keep your original copy until you have checked the restored list.