Thank you for your asking. Are you facing the issue? Please try the following steps to access recovery mode for the Factory Reset:
0. Try to back up your data with USB cable. If you can not access the phone, please check if your google account or microSD card have auto backup your data.
1. Power off the phone, then keep pressing "volume down key"
2. Press "power key" and stop press " power key" once you feel the vibration. Still keep pressing "volume down key"
3. Stop press "volume down key" once you enter [Android Recovery] Screen
4. Choose "Wipe data/factory reset">"Factory data reset"
5. "Reboot system now"
#Hardware Reset Guidehttps://www.asus.com/support/FAQ/1006346/
Please note that once the steps are completed, all data, apps, settings and personal information will be deleted.
If the issue remains after the Factory Reset, please contact ASUS repair center in the country of your residence: https://www.asus.com/support/Service-Center-All-Countries/