The US treasury does/did this on-screen keyboard thing as well (at least up until I stopped needing to login to that website within the last year or two). The "best" method I had around it was to copy the password out of my manager, use developer tools to find the '<input type="password">' element, and add 'value="[paste]"' manually.
I used to bank with WestPac and from memory it wasn’t possible to do this as they had some additional javascript running that would cipher every letter.
