My Apple Watch won’t charge

Hello!

Are you using the original charger?

Are the watch and the charger completely clean?

Also, you should check this article:

If your Apple Watch won't charge or it won't turn on - Apple Support

I would try a force restart, but depending on the battery age, your battery might have reached a point where the charge is too low, and he needs to be replaced because if she goes under a certain voltage, she cannot recover!