Why my oppo a33f show black screen and cant turn on

my battery is low ..so i charge my phone and after that i want to turn on my phone but it shows black screen and also my power button is already broken. my phone show the white light but the screen still black. i try to call my phone and my phone did not ring or show any reaction. i have already tried to charge my phone in 30 minutes but still did not show any reaction. What can I do ?