PowerCore 10000 Redux won't charge my phone

Hey everyone, I just received my PowerCore just by the time this post was created, and I have a question.
How do I activate the PowerCore for it to charge my iPhone X?
I have follow the instructions on the manual, it said to press the button twice to enter “trickle-charging” mode, and it does turn green.
Plug in my Bluetooth earphone, I did. (Earphone didn’t show charging LED)
Press power button again to exit the green light, I did.
Then it said you can charge you device now, which it didn’t.
Am I missing anything here?
Any help would be appreciated, thanks you.

I just realize I haven’t plug in the USB in deep enough, I thought it was haft way in.
The port stop my plug haft way in so I thought it was like that. XD