Does Marketo supports phone text reminders we can send people for events we host like webinars?

You can use webhooks and a provider like Twilio to do this.

As Kristen noted, Twilio is one SMS provider in launchpoint.marketo.com. After some investigation, Informatica's SMS solution is also a good and uses Wehbooks in the same way and seems simpler. Keep in mind a few things:

• did you receive permission to SMS people?
• what is the law in your jurisdiction? Best to get actual permission first during the webinar reg process
• why sms and not email?
• each message has to have a different webhook