Last year, I took a non-credit college course in social media and the instructor introduced these. Long story short, these are pages that allow you to show off your credentials in a somewhat condensed form. To date, I've only used two (Carrd and Linktree) but these were for class projects. In addition to rebuilding my professional website, I'm considering adding one of these as well. Off the top of my head, I can't remember which of the two had better features but the upside is that the yearly host fees cost less than a casual dinner.
Here's a list I compiled recently as part of my freelance blog post. I know there are more link bio apps out there but most of these were linked to Instagram. If you're familiar with these, let me know what you think. Thanks!