How do I send my first SMS flow?

Hello @Stefunny,

Adding to @julie.accardo’s great points, I would further suggest taking a look at both the Creating an Email Welcome Series and How Contacts Move Through a Flow Help Center articles. The experience you are talking about automatically sending customers a SMS after subscribing to a signup form is also known as a List Triggered flow, or more commonly known as a Welcome Series flow. 

This sort of flow functions in response to a customer being added to a list or providing SMS consent. When a contact signups to your form to provide SMS consent, these contacts would typically be provided with a double opt-in text requesting they confirm their subscription. Once confirming their subscription by replying to the SMS, the subscriber would then be consented to SMS and be added to the list associated with the form. In turn, this action of being added to the list would trigger the flow you have set up and send the corresponding SMS to your subscriber. Another article that may prove helpful to further understand and create a SMS welcome series flow would be the Creating an SMS Welcome Series article. 

I hope this helps!

David