I’m not using it to claim that I should be paid more, or that other people should be paid less. Good luck to her whatever she earns, I hope she earns even more than she already does, but her assertion that if she had a penis she’d automatically be paid more is no more true than saying she’d be paid more/less if she was younger/older, more/less attractive, better/worse at acting or whatever else she could pluck out of the air.
If she’d just pointed out that women earn less (in society, it’s not unique to Hollywood although it is also true in that industry) she’d have of course had lots of evidence to back that up.