Use AutoFill to automatically fill in credit card information and contact information.
Important: Never enter your password or credit card number on sites with a “Not Secure” warning. See the Apple Support article Use Apple Cash.
Go to the Safari app above the keyboard to use it at checkout.
When you sign up for services on websites and in apps, you can let iPad create and save strong passwords for many of your accounts. See Bookmark a website in Safari on iPadAutomatically fill in one-time verification codes on iPad