Check the hotspot settings on your phone
Open Settings
Tap Network & Internet or Connections
Tap Hotspot & Tethering or Mobile Hotspot
Select Wi-Fi Hotspot or Personal Hotspot
View the password or hotspot key
Check the hotspot name and password on the same screen
Change the password if needed
Save the new password
Use the hotspot password shown on the device sharing the hotspot
If you cannot find it, check your carrier app or device manual