the only way i've found so far to autofill credentials if you have multiple accounts for a site without having to move your mouse and click the icon in your browser toolbar is to enable automatic suggestions in password fields which grossly violates my "do not speak unless spoken to" guidelines for software
it USED to work with cmd+opt+\ but that just summons the desktop app now which, when you click an account, opens a NEW browser tab with the thing you're trying to sign in to instead of autofilling the current tab
ALSO it just... doesn't unlock anymore when i hit cmd+\ - it just completely ignores the keystroke until i summon the desktop app with cmd+opt+\ which i then have to exit out of because trying to select an account there WILL OPEN A NEW FUCKING BROWSER TAB AGAIN
had this problem when setting win10 up on my new laptop. it's really cool how the 1password legacy browser extension still exists on the chrome web store, but to access it you need to use the wayback machine to find the god damn link.
i still use 1P7 and the legacy browser extension for the simple reason that the newer versions of the software Plain Fucking Suck and i wish agilebits would see sense.