iPhone 13 mini Not turning on
Hi all. I think my iPhone 13 mini got stuck up. I bought it 2 years ago and never used it. I just kept it in my drawer. 2 days ago when I tried to turn it on, it won't turn on. I did the basic troubleshooting to force-start it by pressing and releasing the volume up and down buttons simultaneously and then pressing and holding the side button. The "not-charging" battery appeared followed by the Apple logo. But then, it quickly disappeared and I'm back to a black screen.
I repeated the steps several times and I got the same results. I need help, please.
iPhone 6s Plus, iOS 15