Twilio
Overview:
Visit twilio.com to get an account and that gives you an Account SID and Auth Token (long long random letters and numbers.) and a unique phone number.
On Hubitat, create one (or more) virtual device(s) and assign it the Twilio driver.
Paste in the two Tokens from creating a Twilio account. Save.
Select the Phone number to send from and type the phone number to send to. Save.
Use the Twilio device(s) in Rules and Apps to send notifications.