Hello @milansuthar ,
welcome to the Polycom Community.
Please ensure you always check the FAQ's and/or utilize the community search before posting any new topics or follow up post’s.
The Youtube Video is pretty detailed and will work if done the correct way and steps
Oct 10, 2011 Question: How can I reset / Factory default my Phones configuration?
Resolution: Please check => here <=
The above also describes this without revealing the actual workaround password.
If this all fails please work with SCANSOURCE COMMUNICATIONS who sold this phone back in 28/02/2018
In order to raise a support ticket you need to work with your Polycom reseller as they need to do this for you.
End Customers are unable to open a ticket directly with Polycom support.
If this is some sort of an Internet discounter providing your MAC address or your Polycom devices serial will enable us to look up who would be able to support you. This may not be who you purchased the Polycom device from.
If the unit is no longer within warranty please be prepared to Pay Per Incident / PPI. This is all outlined in detail here
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.