You are likely in the "New Experience" mode of using Office.
New Experience - Microsoft Office - Office 365 - Turning it on and off
I have this turned off in my Word 2021 on Windows 11 but doing so is not easy.

That "New Experience" moves the AutoSave button into the Title Bar. If it is not there, you can still add it to your QAT.
Modifying the Quick Access Toolbar (QAT) in Microsoft Word