My Hp Chromebook wouldn’t work

Hello. I have a HP chromebook and it has stopped working. I was trying to turn on developer mode by holding the buttons: CTRL, REFRESH, POWER OFF since that’s what I searched on google. I did that and it powered of my chromebook (which is supposed to happen from what I read) I read that it’s only supposed to turn off for a few seconds then turn on again. This wasn’t the case. My chromebook turned off and is now impossible to be turned on again since every time I hold the power button nothing happens. The LED lights don’t even come on and I don’t know what to do since this chromebook is what I really need at this moment. If you know how to help me fix it please reply. Thank you.