Help outputting to 1.33 x 1

[ctg115]

Hi, I'm a teacher who will be using OBS to broadcast over Zoom. I'm using OBS on a PC with a 16 x 9 monitor. My students will be viewing the stream on iPads which have a 1.33 x 1 ratio. Can someone help me change my output ratio from 16 x 9 to 1.33 x 1? I want to be able to fill the screen on their iPads. Thanks in advance.