a) Make sure you have peel off the insulation tape on the earbuds, put into charging case and insert the USB cable to charge at least 30 minutes.
b) Make sure your earbuds are not connecting other device.
c) Check if the earbuds are in the pairing mode. The LED flashes blue when the earbuds enter the pairing mode.
d) Turn off the Bluetooth function of your device, and turn it on again.
e) Enable the searching function of your device again.
f) Try to restart the earbuds.
g) Try to reset the earbuds.