Bluetooth
My Bluetooth on my iPhone won’t connect to anything it won’t even display the icon at the top when it’s on. How can I fix it?
iPhone 7 Plus
Starting from iOS 12, the BT icon doesn't appear on iphones status bar any longer.
That being said, what's happening when you try to pair a BT device to your iPhone?
Have you already read these support articles?:--> Pair a third-party Bluetooth accessory with your iPhone, iPad, or iPod touch – Apple Support
and/or this one:--> If you can't connect a Bluetooth accessory to your iPhone, iPad, or iPod touch - Apple Support
Regards
Giulio