I am not sure he even has it. This is the man who wrote The Art of the Deal. Trump understands persuasion and show business. Like me, he is extreme sneaky and dishonest and lies his ass off whenever necessary.
If he carries on being the President with Covid, like it is nothing to him, thereby stressing he is "Iron Trump", the bestest fittest biglyest president ever, and Joe Biden is a puny little masked up geriatric dork hiding in his basement frightened of a virus that Trump just shrugs off, this is great image management for his final weeks of campaigning.
Those debates were going nowhere and were of no value to Trump. He is already President. Why lower himself to be attacked by Biden and the moderator?
Americans love tough leaders. This shows he is tough. Has Coronavirus and just gets up and goes to work. Since he is President he is an essential worker and can easily quarantine himself on the move and even speak at events being a glass screen. They just bubble off a part of Airforce 1 and he gets on with it.
Trump having Covid will actually increase the media attention on him and thus take it away from Biden. Which is what he did to Hillary.
If he is asymptomatic and does not take to his bed, but carries on regardless, then I would very strongly suspect he does not have Covid at all. It is impossible to prove, so we will never know. Since you can catch it twice it does not prove he did not have it even if he gets it again.
You'll never see his Tax records or his Medical records. So he can take the secret to the grave with him.