A way to enable search for user profiles?

Hi.

I'm trying to see if there's a way to enable Wordpress's not-so-great search function to be able to search user profiles. Yes, I know plugins like Revelanssi Premium can apparently do this -- but this is for a non-profit site, and we're already racking up a lot of costs for various things in relation to building this site. We're trying to keep costs down as much as possible so it goes into the non-profit. Plus...it just seems so silly that the only way to enable a feature that seems so basic is to pay for it!

Are there are other solutions out there that are free, which can include user profiles in search results? We're using "Ultimate Member" for profiles, but apparently they act the same as WP user profiles in terms of search (and therefore don't work with Relevanssi's free version).

Any help, suggestions of guidance would be greatly appreciated!!