To use a TF card on a Bluetooth speaker, the TF card must be inserted into the speaker's SD card slot. Once the TF card is inserted, the speaker will automatically begin playing the audio files that are stored on the card. Most Bluetooth speakers will have a built-in process for playing music from a TF card. For example, on some models of JBL Bluetooth speakers, you can press the "Play" button to start playing music from the TF card.