Just activating Bluetooth on the Oppo smartphone is not enough to send or receive files. Once activated, both devices must be paired with each other. Depending on the device to be paired, the connection must be approved by both devices.

The Oppo-Smartphone can be connected to many devices such as headsets, Bluetooth loudspeakers, television, car/car radio, hands-free car kit and much more.

Android 10 | ColorOS 7.0
Step 1:  Open the  Settings
Step 2:  Tap on  Bluetooth
Step 3:  Choose desired  Device
  1. Open the Settings
  2. Tap on Bluetooth
  3. Choose desired Device

Oppo Instructions