Help with using external microphone into iPad Pro

I'm helping a friend with an iPad Pro. Two questions about using an external microphone:

1. She would like to plug in an external microphone (TRRS) via a lightning port adapter and use the internal iPad speaker for audio output (during a Zoom conference). First attempt indicated the microphone audio was indeed available to Zoom but the iPad speaker was not working. Is it possible to use external mic audio input at same time as internal speaker audio output? If so, what configuration settings are needed?
2. Is it possible to feed the external microphone audio into two apps simultaneously on the iPad Pro or is there an inherent limitation that would prevent this?

Thanks for any help!