If AutoFill doesn’t work in Safari on Mac
If you can’t fill in information you previously entered on websites, try these suggestions.
Choose Safari > Preferences, click Passwords, then make sure “AutoFill user names and passwords” is selected.
Note: When you select the “AutoFill user names and passwords” option in the Passwords pane, “User names and passwords” is also selected in the AutoFill pane of Safari preferences.
Make sure any information you want to be filled in is saved in Contacts. Safari can fill in only contact information that is in Contacts. For example, if a form requires your phone number but it isn’t on your contact card, you must fill it in manually.
Make sure the webpage has fields AutoFill can complete.
Safari may be unable to tell which fields are for user name and password, credit card number and expiration date, and so forth.
If your Mac has Touch ID, and you want to use Touch ID to easily fill in user names and passwords or credit card information, make sure you select “Require Touch ID to AutoFill” in Safari AutoFill preferences.
If AutoFill still doesn’t work, the website may not allow it.