I currently have an OpenPhone account with an SIP phone number. I would like to automate SMS messaging. I looked into Twilio and thought it could be a good solution, except I seem to run into the problem that the number needs to be ported at both OpenPhone and Twilio at the same time.
I have trouble understanding the need for porting a number for Twilio. I remember needing to port the number to OpenPhone to use it.
Could there be a work around that allows me to code my own automation using some other API or then send messages from OpenPhone or any other SMS service that I could access online (or from an APP)?

I looked into Zapier, it could work but the solution would require the upgraded plan. I would like to find another solution that would cost less to implement.

In summary I need:

• the same phone number as I have now
• Customizable SMS automation
• Low volume SMS required
• Access to an online UI (same or similar functionality as does OpenPhone)

Thank you for your help in advance!