@PD
Buy a cheap one on amazon.
https://www.amazon.com/Retekess-Wireless-Broadcast-Transmitter-Station/dp/B088KLF8DJ is an example.
We used a cheaper one without problems.
Feed the sound from the mixer.
We could not move our Qu so we set up a small prosumer mixer in the parking lot for outdoors use.
Pick a clear channel to set the FM transmitter to use.
https://radio-locator.com/cgi-bin/vacant
Verify it with a Radio to be sure.
Check any other instructions with your unit.
Probably needs external power supply so you need an outlet.
Range probably means put the transmitter in the parking lot not in the church building.
Turn it on.
Tune your FM radio to that frequency.
Start the show & enjoy.
There is really nothing to using them except the risk the FCC might object if it is not compliant with their rules.
Some transmitters on amazon seem to be overpowered for FCC approval.
A license is optional depending on the power transmitted, possibly other factors.
https://www.fcc.gov/consumers/guides/low-power-fm-lpfm-radio
https://www.ctcumc.org/drive-in-church-resources
https://www.radioworld.com/news-and-business/news-makers/low-power-radio-faqs
https://recnet.com/drive-in-church
Some folks claim they FCC dont care as long as you are not interfering with other broadcasts.
NOTE: they are not driving around trying to find illegal transmitters.
But if someone sent in a complaint then they would follow up on it.
Fines can be huge if they do clamp down on you for illegal broadcasting.