iPad air isn't powering on

I have had my iPad air for 4 years now. I use it for school so there are quite a lot of documents that I need on it. It has been working fine up until recently. The last time I used it, it was on 30%. Now the screen is black and it does not power on. I've tried charging it with multiple chargers, forcing it to restart and connecting it to iTunes through my laptop, but it has stayed the same for the past few days, just the black screen with no sign of power. I'm not really sure what else to try.

Any tips would be greatly appreciated