Urticaria related. Is this due to covid?

I was covid positive couple of weeks ago and now I'm on the recovery stage and my body is full of rashes which burn, and pain alot. I visited a dermatologist who has given me amorlofine cream for buttocks and cuticol solution for the other body parts along with 3 tabs and terbinafine dusting powder. my query is how should I use the dusting powder ? Is it supposed to be dusted after applying amorlofine cream only ? Or can the powder be used to dust the part where cuticol solution is applied .? I mean can I dust the part with dusting powder after applying cuticol solution on remainng parts or is it related only to buttocks and amorlofine cream. And should it be dusted once or twice a day?? I've attached pics as well. And is this due to covid ? Can this be cause for black fungus as ppl have told it happens with skin as well .