ipad changing amount of paticapents see on screen

after the lateset update   ihave a ipad pro   11 inch  3ed generation  with version 16.4.1 

after updateing zoom i can see over 30 particapents on screen how can i adust the amount per screen, cant seem to find a way i know i can switch to speeker view  but thats not what im wanting i want to reduce the amount you see per screen