Increase Number of Invites in Meetup

I would like to build my Meetup into an Event… Zwift said they would have to see me “fill” my Meetups to 50 riders. However, it’s hard to get 50 people to attend a Meetup when you can only invite 50. It would be easier to get 50 riders in my Meetup if I could invite a larger number, like several hundred.