Give small amount as bounty for the testers then you will see people rushing into your site.

Maybe that could be their last resort if they really didn't get good beta testers but for the meantime it's better to look active traders and give first hand review in the site. But yeah I would suggest to state here the offers that beta testers can have so we can decide whether it's fair or not.
Anyway, I was expecting that your domain is .com and not .io
Is this the one?
https://nominex.io/