I know people love to say that people who say “kids today are lazy” are out-of-touch… but… this is just a Google search away. And you can buy them everywhere. And you can ask literally anybody. I never had a problem figuring this out with my absentee-ballot.
Yeah, all you have to do is search online for the nearest post office. I guarantee you that they have stamps.
Searching for a post office is even more complicated than it needs to be. You can buy stamps at Walmart at any checkout lane in the same transaction as you get your four lokos or whatever the young adults are buying these days.