Button "Save windows and tabs of the current session" is no longer available in the current Firefox version 152.0.1

Hello everyone, Until a few days ago, Firefox version 140.12.0esr included a button to "Save windows and tabs of the current! session." Unfortunately, this feature is no longer available in the current version, 152.0.1. However, for many Firefox users, saving the windows and tabs of the current! session is absolutely essential. What options are there now to resolve this issue? I would appreciate any suggestions! If there is no way to restore this feature, I, too, will unfortunately have to switch browsers after 20 years as a Firefox user. Many thanks in advance for your help and any information. Best regards, Norbert