Hi, you haven’t stated whether the Air is turning on at all, so I’m presuming that the air is on but the display is not.
This is a link to instruction on how to reset
NVRAM, PRAM and SMC on any Mac at Macworld.com
https://www.macworld.com/article/224955/how-to-reset-a-macs-nvram-pram-and-smc.html
You should find the reset type you need if you read the article.
Hope this helps