You can send SMS messages to your clients directly from your Bitrix24 CRM using Twilio integration.
Create a new Twilio account
First, you need to create a new Twilio account (in case you don't have one already).
Go to twilio.com > click the Sign up button at the top right corner.
Complete the form and click the Start your free trial button.
Go to your email inbox to verify your email address.
Specify your phone number and click Verify. Then enter the verification code that has been sent to the specified number.
You will be redirected to the Twilio console, where you can get a new Twilio phone number. Click Get a Trial Number.
You will see your new Twilio phone number in a pop-up window. Click Choose this Number.
Then click the button with three dots > Programmable SMS.
Click Settings > Geo Permissions and select locations you're going to send SMS messages to.
Navigate to the Twilio Console Dashboard and copy your ACCOUNT SID and AUTH TOKEN.
Configure Bitrix24 and Twilio integration
Open your Bitrix24 account > click CRM > Settings > Integration > SMS Notifications via twilio.com.
Paste your Twilio ACCOUNT SID and AUTH TOKEN to the corresponding fields and click Connect.
After Twilio has been successfully connected to your Bitrix24, you can start sending SMS messages right from your Bitrix24 CRM.
How it works
To send messages from Bitrix24, open a CRM element (lead, deal, contact or company), go to the SMS section, enter the message text and click Send.
In case you have several Twilio numbers connected to Bitrix24 CRM, you will be able to choose the number from which SMS will be sent.