Welcome to the community forum.
We’ll assume a Fairphone 4 (from your profile)?
You could try whether different chargers or different cables might help.
You could also try to carefully remove dirt or lint from inside the port using air or a pick of some sort (but no metal!).
Perhaps you happen to have fairphoneangels in the vicinity (see angelsmap) you could ask whether they would be prepared to take a look?
If the slow charging endangers the battery charging level (don’t let it run to 0%, if it can be avoided), perhaps use the time you still have to look for a fitting external smartphone battery charger. Here’s some inspiration … External universal chargers for Fairphone batteries.
With such an external charger it is also easier to continue to use the phone while looking for a solution to the charging problem.