Looking to send SMS for specific Tag

Hope everyone had a Merry Christmas!!

I’m looking to send a text message to a Client when a specific Tag is applied.

Any recommendations?

I use Zapier for quite a few things so I’m going to “play around” with that but I’m looking for SIMPLICITY because it’s the boss that’ll be doing it - Need it to be VERY user friendly.

Thanks in advance!!

Cindy