A cam girl can never be a mistress even though they proviede mistress services.
To enjoy the fantasies, you much approach a real mistress who does only those.
There are many ppl roaming on X claiming that they do provide femdom service even without knowing what it is. Their motto is to just grab the money, beware when you are opting for a session and avoid paying if they demand any adv to share details before the session confirmation.