Shameless plug: I made Hangswith so I could book a meeting with a career mentor and pay them the equivalent of a nice bottle of wine for an hour of their advice once a quarter.
It's basically Calendly with a more personal profile which makes you easy to find via search engines and easy for someone to find a time, book you, and pay you.
EDIT: if you offer career mentorship, or chess coaching and wanna join, you're very welcome to!