There are two ways to connect a lavalier to a Bluetooth speaker, depending on the type of microphone you have.
If you have a wireless microphone, all you need to do is connect the mic's receiver with the emitter of the Bluetooth. (This will allow you to use your app to control the settings of the Bluetooth speaker.) Once connected, pair your microphone with the Bluetooth speaker by tapping the “Pair” button on your microphone and then choosing “Speaker Pairing” from the list that appears.
If you have a wired microphone, you will first need to preamp it so that it can be connected with the Bluetooth speaker. To do this, plug one end of the cable into the input on your preamp and plug the other end into an output on your Bluetooth speaker. Then power up both devices and start pairing them by clicking “Pair” on your wired microphone and select “Bluetooth Speaker Pairing