"I lost my tabs after the update — What can I do?
You may notice that after updating Firefox to version 94, the tabs from your previous session were closed. To learn how to restore a previous session, visit How do I restore my tabs from last time? Alternatively, following the prompts in the Open previous tabs? one-time notification that will appear after the update will also allow you to restore the tabs from your previous session. "
https://support.mozilla.org/en-US/kb/how-configure-close-tab...