Unlike macOS, there are no browser extensions to integrate LastPass on iOS or iPadOS in the web browser.
Although I've installed the LastPass app on my iPhone & iPad, How do I access my passwords from a web browser?!?!?
Chrome Users: Please note that LastPass has problems in iOS/iPadOS and as of 13.3.1, the fault is still present. All is not lost however as LastPass in the below example is tested and known to work correctly with Firefox as of iOS/iPadOS 13.3.1.
Before you can access any passwords, you must have the LasstPass app installed on your iPhone/iPad and be logged-into the App with your LastPass Master Password
Although this example uses Firefox, the process is almost the same for Chrome users.
Tap the password offered in the LastPass dialog.
Although not a very intuitive process, using LastPass with a browser on iOS/iPadOS it's still pretty easy to use.