Can anyone diagnose this?

[Bzyn21]

It has two of these white spots? I’m attempting Melafix.

 

[Valkyrie_Lips]

What is the tank size, stocking and parameters? How often do you do water changes?

 

[Colin_T]

What are we looking at, the white mark on the black moor, just below the dorsal (top) fin?
If yes, it looks like a couple of scales are missing. It should heal up by itself without any issues.

To help reduce the risk of disease, do a 75% water change and gravel clean the substrate every day for a week.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

If it gets worse, post more pictures.