How can we change the ringtone on the Oppo smartphone? there is a simple option in the settings where we can choose from standard ringtones. on dual SIM devices, the ringtone can be set separately for each SIM card, and it is also possible to use a separate ringtone.

Android 10 (ColorOS 7.0)
Step 1:  Open the  Settings
Step 2:  Tap on  Sound & vibration
Step 3:  Tap on  SIM1 Ringtone  /  SIM2 Ringtone
Step 4:  Choose desired  Ringtone
  1. Open the Settings
  2. Tap on Sound & vibration
  3. Tap on SIM1 Ringtone / SIM2 Ringtone
  4. Choose desired Ringtone

Oppo Instructions