With your new sim card, go to My Account to request Change Sim card (you might want to use a desktop or laptop computer )
(If you are unable to login as you don't have a phone to receive the 2FA code: On the screen it is expecting you to enter the code, click Didn't get the code? or Resend code and then choose Send email)
Then go to Profile page, click on the Pencil besides the sim card number, follow the steps to enter the new sim card number and complete the change sim card request
(or direct link: https://myaccount.publicmobile.ca/en/account/profile/change-sim-number )
After the sim card is updated, wait 5 mins, then reboot your phone and it should be good
