The Bluetooth of my headphones does not seem to work

The Bluetooth of my headphones does not seem to work
I have a pair of JBL headphones that is able to play through Bluetooth and through an aux chord, and they work perfectly through the aux chord but when I try the Bluetooth I cant find the headphones on my phone, what is a way I could fix this

ANSWERS:

Have you tried pairing to other devices than this one cell phone?