Headphone jack output TO Bluetooth headphones.

Help. I'm new at a church as the sound guy, and they have an amazing sound system that is run by a tablet. The amplifier is actually on the stage with no cable runs back to where the soundboard is. I would like to use wireless headphones to be able to solo each microphone, but because there are no wires to send the audio signal from the headphone jack / control room jack back to where we sit to run everything, I have no way to hook the headphones up. I need a Bluetooth amplifier that will plug into the quarter inch jack and broadcast to headphones. Does anybody know of such a thing. All I can find are Bluetooth receivers to plug into microphone inputs. Thanks.
How far away from the mixing position to the control room jack? Are there any walls in between the two locations. Reason for asking is Bluetooth has a rather limited range. What is the tablet using, wi-fi? Does existing wireless the control system support getting an audio link through the tablet?

OTOH if you just want to try something inexpensive, looks like there are a number of off the self solutions: https://www.amazon.com/Multi-stream-Bluetooth-Transmitter/s?k=Multi-stream+Bluetooth+Transmitter Some of them appear to accept line level inputs, so they might be able to plug right into your jack. Maybe need a plug-size adapter cable or something, but the idea may be pretty trivial to hook up and test out.
68 ft from the amplifier to the soundboard. Nothing in between except open room. The tablet is connected through the Wi-Fi network but does not carry any audio signal. When we first bought the Bluetooth headphones we assume that I could hook the headphones to the tablet, but there's no audio signal from the amplifier mixer 2 the tablet. The instructions with the amplifier mixer says that there is a control room output jack to run audio to wherever you're mixing room is, but is designed for a 1/4" wired jack ..
With that distance you would probably either need professional level wireless audio of some kind, or maybe a wi-fi solution, or else just have someone run a cable out to your mixing location. Cable might end up being less costly and more reliable in the long term so long as your mixing location is always in the same place.

Problem is Bluetooth is only supposed to be good for about 30' maximum distance.