What is this floating button on my Pixel and how do I get rid of it.

Hello @thewoolleyman

Tapping the floating button turns Accessibility for 1Password on and off under Settings > Autofill. In short, this is not something you will likely need to do so it's best to turn the shortcut off.

We developed our Accessibility feature to help pick up slack from Autofill where Autofill is blocked or can't detect the fields. Our Accessibility feature is built into accessibility services which includes more conventional accessibility services such as TalkBack and text to speech. While it is quite useful to switch conventional accessibility services on and off without sifting through the settings app you're less likely to be switching Accessibility for 1Password on and off frequently.