SIM Pin

I purchased an iPhone 13 through Spectrum Mobil. I would like to change the SIM Pin and have tried 1234 and 0000. Both of these numbers I found online. Now I only have once chance left. When I go to Settings, Cellular, SIM Pin, the SIM PIN line has a toggle and the "Change Pin" line is not active. If I toggle SIM PIN I get a screen to "Enter PIN to lock SIM. 1 attempt remaining". I called Spectrum Mobile and they had no clue. Neither do I. Help anyone?