When unscrupulous salesperson Eleanor accidentally ends up in the Heaven-like Good Place in a case of mistaken identity, she must learn to pass as a good person if she is to avoid discovery and be cast into the Hellish torment of the Bad Place.

This could probably be trimmed a bit.

Also - no need to give her name in the logline. It's just blowing out word-count.

When an unscrupulous salesperson accidentally goes to heaven, she enlists the help of an ethics professor to help her pass for as a good person, so she doesn't get sent to hell.

Nice. You've included a flaw for the MC and her predicament/story world in a way that shows how they will be in conflict. And even managed to squeeze in the stakes.