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Choose Create Records option under Elements section in Toolbox and it choose Object as SMS Message and set it’s Record fields as following:-
LeadParent_Record_cId->Record Id RecordTpeIdto which the SMS Message will be linked to
RecordTypeId->Enter the Record Type Id
Customer’s Phone-> Phone field on Object Record.
Message Type-> SMS
Text Message->Enter the Text Message
User First Name->User First Name
User Last Name-> User Last Name
User Phone-> User Phone
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