How to pair Alta HR to Bluetooth again?

[Jetski2]

 I accidentally let my fit bit Alta HR lose the Bluetooth connection by telling it forget this device.

I would like to make my fit bit sync to Bluetooth again on my iPhone 7 could you give me some helpful tips to make this happen

Moderator Edit: Clarified Subject.

[HPfanslytherin]

Won't you lose all your data?

[SunsetRunner]

Hi @HPfanslytherin - As long as you do not do a Factory Reset, you will not lose your data.

[KBeyes]

My Alta HR is showing “not enough data  available “ when I use the exercise tracker. Also it shows the wrong time on the exercise tracker but not on the wrist device. I have turned on and off Bluetooth, removed device, added device as a new device and all the recommended steps above yet it is still not tracking. What is the next step?

Thank you! 

[UGH2020]

My fitbit doesn't even show up on the bluetooth list of devices.