To iOS and Android phones
Step 1: Open the lid of the charging case. After that, the earbuds will turn on automatically.
Step 2: Press and hold the multifunction touch button in the back of the charging case for 2 seconds. When a white light turns on in the case, the earbuds will be ready to pair to any device.
Step 3: Go to the device’s Bluetooth settings.
Step 4: Select “OnePlus Buds Z”. If a password is needed, type “0000”.
Step 5: After that, the light will turn off, and the pairing will be done.
To PC (Windows)
Step 1: Turn on Window’s Bluetooth.
Step 2: Go to the settings.
Step 3: Go to “Bluetooth and other devices”.
Step 4: Click on “Add device”.
Step 5: Click on Bluetooth.
Step 5: Open the lid of the charging case. After that, the earbuds will turn on automatically.
Step 6: Press and hold the multifunction touch button in the back of the charging case for 2 seconds. When a white light turns on in the case, the earbuds will be ready to pair to any device.
Step 7: Select “OnePlus Buds Z”. If a password is needed, type “0000”.
Step 8: After that, the light will turn off, and the pairing will be done.
Source : thephonetalks.com