iPhone XS Max not charging

I plugged my phone in when it was on 10%. I came back half an hour later and seen that my battery has dropped down to 4% but there is a lightning bolt. I changed the charger and plugged in a genuine apple charger and left it for around 1-2 hours and came back and it was still on 4% with a lightning bolt. This is the first time I have encountered this problem, and I am unsure of what to do. If anyone knows a solution, please don't hesitate to reply.

Thanks!