It depends on the situation
If it has not been used for a long time, the power loss is serious and it cannot be charged. You must activate it. There is a device to fix it. electric vehicles called battery repair instrument, actually it activates the exhausted battery, you can try it.
If it suddenly stops charging during normal use, there may be faulty cells in the battery or the charger may be broken. Try another charger. If the battery core is broken, there is nothing you can do other than replace it.