Connecting two iPads as extended displays for MacBook Pro M4 Max

Hi, I’ve got a MacBook Pro with the M4 Max chip and am trying to connect two iPads to use as extended displays, in addition to the computer’s screen (so three simultaneous displays total). I’ve read that the M4 Max supports up to four displays, but can’t figure out how to make it work. From the Screen Mirroring or Display Settings menus, I’m able to extended the display to either one of the iPads, but not both at the same time; while one is active (and the icon colored blue), the other is just greyed out and waiting. I’ve tried doing it both over WiFi and with the iPads directly connected to different USB-C ports on the Mac. Are there instructions somewhere on how to do this, or is it not possible with iPads (or mine, at least, since they’re both a few generations old)?

The specs on the iPads are:

iPad mini (5th gen), A12 Bionic chip with neural engine

iPad Pro 12.9 inch (3rd gen), A12X Bionic chip with neural engine and embedded M12 coprocessor

Thanks!