that means the sim not connected to the network
Try to take the sim out and put it back firmly, try on another phone as well if possible
of course, check My Account to confirm if your account is active
if you need PM to help, you might need to message them as you wont be able to receive 2FA text, message them here: https://productioncommunity.publicmobile.ca/t5/notes/composepage/note-to-user-id/22437
CS_Agent will reply to your community inbox between 9AM-10PM EST (Mon-Sun), check here:
https://productioncommunity.publicmobile.ca/t5/notes/privatenotespage
