My IPhone 6 won't turn on when it shows its charging?

I've had it plugged in all day but is still shows the charging sign whenever I press the home button/power button and it will not power up. How can I make my phone turn on?

Cross your fingers and try a hard reset. To hard reset your iPhone on an iPhone 6S or older, press and hold down the Sleep / Wake button (the power button) and the Home button at the same time, for at least 20 seconds or until the Apple logo appears on the screen.

- Google

otherwise, you may have to send it in for repair, or at least get a battery replacement at your local Apple store. Make an appointment online ahead of time so you don't have to wait long.

Hold the power button down for more than 4 seconds

Try unplugging the phone and wait till charge icon is gone then turn on phone and plug in charger