Why wont my Bluetooth earpiece with mic, work in calls, even i cant record audio

[Android Central Question]

So i bought this cheap 😅 i7s tws Bluetooth earphones, i can listen to music but while making a Call, if the call option is on Bluetooth he cant hear me but i can, and if the option is on earpiece he can hear me but i can't.

 

[anon(10614692)]

This is from the manual:-
Bluetooth usage: 1. Making phone calls: Be sure the earphone connected with your mobile phone, and then you can make phone calls. When making calls, there is only one side earphone working, and there’s incoming call, it would broadcast calling numbers. You answer the call by slightly press the power button one time and refuse to answer by quick press the power button 2 times. When the earphones are in music mode, you dial your latest number by quick press the power button 2 times (redial the latest number).

Are you following this routine? There may be a compatibility problem, with your phone if you are following these steps.