You can get it to recognize fingerprints or a short version of your password if it's even been fully unlocked for the current phone session. It's a little fiddly and may not meet the level of security you're looking for, but it's an option.
I don't use any plugins. I just copy/paste, which if you're doing it from the app stores the copied parameter in memory for a ~15 seconds, after which it is flushed.