I use Twilio/Sendgrid paid services. It was a bit of a pain to setup initially but it works perfectly.

They offer a few possible setups and service but the one I stumbled through making was buying a phone number from them and use it with their messaging API. In my case as a business sending text alerts/messages you have to follow some rules like allowing a way for customers to opt out, and providing stuff like text consent, privacy policy, terms of service, etc. But once you get through the loops it works great with something like this.

    ' Body message with URL
    bodyMessage = "Your invoice is available to pay at https://myurl.com/estimate.asp?code=" & EstimateUniqueCode
    
    ' Escape the double quotes for Windows CMD
    bodyMessage = Replace(bodyMessage, """", """""")

    ' Build curl command
    curlCommand = "curl ""https://api.twilio.com/myAPIinfo/Messages.json"" -X POST " & _
                  "--data-urlencode ""To=+1" & PhoneNumber & """ " & _
                  "--data-urlencode ""From=" & MyTwilioNumber & """ " & _
                  "--data-urlencode ""Body=" & bodyMessage & """ " & _
                  "-u MyOAuthCredentials"
    
    ' Launch curl via Shell
    shellCommand = "cmd /c " & curlCommand
    Shell shellCommand, vbHide
    
    MsgBox "Text Message Sent"

Thanks Adam.  Not familiar with "Sendgrid".  I did notice that opt out stuff when I was looking at ClickSend.  Will research.