That's not good @Liamp972
Try a different charging cord and charging plug if you can.
If you perform a forum search and or Google search you'll find various generic troubleshooting tips to try.
As a last resort back up and factory reset.
A Samsung Experience Store / Samsung Service Centre can take a look at the phone for you.
Current Phone > Samsung Z Fold³ 5G. > Software : Android 12 ~ Samsung One Ui 4.