iPhone not charging more than 1% and keeps turning off

My iPhone 13 Pro was at 1% so I plugged it in but it's not charging. It says "0% left" on the screen, 1% (and no lightning symbol) on the top right corner and "1% charging" if I go in the settings. What should I believe?

When I plug it in I can hear the charging sound but then the phone stays on 1%, works for a few seconds and then it turns off.

I've tried different cables and even cleaning the charging port. I've soft-resetted it by clicking the volume buttons and the on/off button but it just restarted and kept not charging.

My iPhone is not updated to iOS 18 but it worked just fine until today, also it's refurbed so the battery is not recognized as an original part.

I can't update it with my Macbook because I don't have the storage to do the back up.

The situation started about 10h ago and I've been trying to turn it on since, keeping it plugged in.

Can you help me please? Thank you