port phone number

Yesterday I added a phone to my straight talk account and activated it. The sim card from the old phone doesn't fit in the new phone. How do I port the phone number from the old phone to the new straight talk phone? Thank you
https://www.straighttalkwirelessforum.com/
https://www.straighttalkwirelessforum.com/viewtopic.php?f=6808&t=1286772