Hi Camomaster1,
Thanks for using Apple Support Communities! I see you're having an issue with websites using the AutoFill option, and I'd like to help.
Verify that at Settings > Passwords & Accounts > AutoFill Passwords is enabled.
At Settings > Face ID & Passcode > Password AutoFill should also be enabled.
If you want credit card information saved and used with AutoFill, at Settings > Safari > AutoFill > Credit Cards is enabled.
When you're asked if you want to save either a credit card, or user name & password, select to do so.
More info can be found here: Automatically fill in forms in Safari on iPhone
If you'd like your other devices, which use the same Apple ID for iCloud, to also have the saved information. Turn on iCloud Keychain: Set up iCloud Keychain
Take care!