If so, where do I get the extension and how do I install it? Using iOS 12.2 on (original) iPad Pro.
1Password Version: 7.3
Extension Version: Not Provided
OS Version: iOS 12.2
Sync Type: iCloud
iOS Apps don't have external extensions so if you have 1Password installed you already have its filling extensions. Though it looks like you'll want to use iOS 12's Password AutoFill feature here, you can read about and configure that with the instructions on https://support.1password.com/ios-autofill/
On behalf of Rudy you're very welcome.