The only reason that you don’t find many spelling mistakes in the works of famous authors is because their publishers have people who are paid to find, and often fix, those errors before the book or whatever goes to print. You can still find spelling mistakes, if you look.
I am willing to bet that no applicant has yet been rejected because of a couple of spelling mistakes, unless they are pretty clearly the result of being unable to spell, rather than a typo.
If you, say, consistently mix up their, they’re, and there, it could have a negative impact, but a few unrelated errors or typos wont have any affect at alll.