If it is like most sweepstakes, the odds that any given user will win will be so tiny as to not really make it worth the effort of using edge or bing.
The rules indicate that "if you have a Microsoft account you’re already a member." <https://rewards.bing.com/sweepstakes/million/about>
As few hundred million accounts in the eligible regions. That's around the same odds as a Powerball lottery.
If it is like most sweepstakes, the odds that any given user will win will be so tiny as to not really make it worth the effort of using edge or bing.