FM Radio - not a radio channel
I need to find a special frequency which is not a radio channel. But no matter where I look I cannot find a program or anything where I can choose my own frequency? I can om my Samsung (work phone) - but I want to do it on my Iphone XS.
Any advice?
I need it for an event where we alle need to listen to the same frequency from the car - due to Covid 19.
Thanks
iPhone XS