Carsifi by default use 5Ghz WIFI as hotspot. If you don't see a WIFI or Bluetooth with the name Carsifi-XXXXX(XXXXX-any number and characters) after the adapter start flashing green on your phone, please try the following solutions:
1. Try to make a full factory reset https://support.carsifi.com/support/solutions/articles/69000813494-how-make-full-factory-adapter-reset
2. Try enabling the "Use only 2.4Ghz WIFI" option and check if your phone can see Carsifi-XXXXX WIFI.
3. Try another phone or PC to make sure issue is on the Carsifi side, not your phone