Job pays per client but wants us to come in early for a meeting. Be a “team player” or call out the legalities of the situation?

I tutor & started working here not too long ago and was required to do a unpaid shadowing before I started the job. Now today the manager called a meeting but I was never paid for the shadowing so I know I won’t be paid for this meeting but I like to be compensated for my time whenever I’m required to be there. I’m sorry not sorry. Can I just not show up?