I am looking for a low cost SMS/Texting app that works with TEAM for texting with applicants outside our organization without having to add to a Team Channel or meeting

Question

We are a non-profit organization in the early childhood education & nutrition space and we are looking for a SMS/Texting app that will work within our Teams Environment that will allow our HR Team to communicate with applicants outside our organization. Most of the texting apps are added to a channel or meeting and we are looking for one that can be used with our existing TEAMS number. Our HR Team members have a Teams Phone with Calling Plan and Office 365 E3 licenses.