When I have received a call on the web browser, I want to be able to easily press 1 or 2 to receive or reject the call, so I don't have to fumble around looking for the dialpad.

Perhaps consider that once you connect and hear the announcer say "Press 1 to accept, Press 2 to send to voicemail", the dialpad gets shown automatically, or that 1 or 2 buttons become active on the UI where the phone number is being shown.