I placed my bet a while ago on Sportsbet.io. It doesn't have the Trump and Biden options, but you can bet on the party winning the presidential elections, and given that the candidates have already been chosen, it's basically the same thing IMO. Moreover, in case, say, Trump doesn't make it due to COVID-19 or something like this, the main competitors will still be those of the Democratic and the Republican Party, so this bet feels safer than the bet on names. Here are the odds:

On Sportsbet.io you can also bet on the party that will win in a particular state if you're interested.
I think this gambling place is the safest place to participate in the new presidential election event in America, indeed the reason you use is right that when Trump is exposed to Covid they people expect their death and it seems that many don't like trump, the meaning is very clear. that trump will lose this election.