I went looking for this exact thing last month after rereading the physical copy. My local library uses Libby and Hoopla, and 'A Wizard of Earthsea' was available on both as an audiobook. All I needed was a library card number. The narration was good, a solid listen for my commute. Some library systems have a better selection than others, so if yours doesn't have it, you might check if they offer reciprocal borrowing with a larger city library. It’s a bit of a process, but it’s how I got mine without spending a dime.
Spotify now has a bunch of audiobooks included with a premium subscription, too. I haven’t seen Le Guin's work pop up in that free catalog yet, but it’s worth keeping an eye on as their library expands. Honestly, the legal free options are mostly library-based or these new subscription perks. Anything promising a straight ‘download’ from a random site is usually trouble.