Your other thread was answered, but again, how old is tank ?
See your other post and please refrain from cross posting which takes away from others seeking answers, while I understand urgency. According to pic, this fish is Moribund and in deep distress and may or may not make it. I cant offer medication or such to perk it up as fish looks past that point.
Increase oxygen to see if perks up but hope for the best and expect the worse.
Which I could offer more positive words