You can use Twilio for Salesforce to send customized bulk SMS messages to all members of a campaign. Before you get started, you should recognize two important points:
Use of the SMS Campaign Component requires users to have access to the Twilio Messaging folder in order to display potential deliverability ratings. If a user does not have access to this folder and the reports it contains, the component will display an error.
This short video will show you how to set up the SMS Campaign component using Lightning, but you can also jump down to a step-by-step guide.
Navigate to one of your campaigns. In the top-right corner, click on the gear icon and then click on Edit Page :
In the sidebar of the Lightning editor, go to the Custom — Managed section, and grab the Twilio — Bulk Message Builder component and drag it onto the page layout:
If you don't see any custom custom components, you probably need to enable MyDomain for your Salesforce organization. You can read more about enabling MyDomain in Salesforce's documentation.