Hi cosmos66,
Thanks for posting in Apple Support Communities.
We understand that you're unable to pair your Fitbit. If your Fitbit is in pairing mode and you have Bluetooth enabled in Settings > Bluetooth on your iPhone, you will need to work with Fitbit support on how to pair the device if you're able to pair other devices, but this specific device will not pair.
"Pair your device with a Bluetooth accessory
- On your device, go to Settings > Bluetooth and turn on Bluetooth. Stay on this screen until you complete the steps to pair your accessory.
- Place your accessory in discovery mode and wait for it to appear on your device. If you don't see it or aren't sure how to make it discoverable, check the instructions that came with your accessory or contact the manufacturer.
- To pair, tap your accessory name when it appears onscreen. You might need to enter the PIN or passcode. If you aren't sure what your PIN or passcode is, check the documentation for your accessory.
After you pair your accessory, you can use it with your device. To pair multiple Bluetooth accessories, repeat these steps. If you have multiple Bluetooth devices paired with your iPhone or iPad, you can choose which audio source you want to use."
Pair a third-party Bluetooth accessory with your iPhone or iPad
Regards.
