You can refer to the below link which includes the process for integration of the Cisco IP phone using LSC cert with ISE. Hope this will be very helpful for you.
https://integratingit.wordpress.com/2022/02/11/ise-ip-phone-authentication/
------------------------------------------------------------
If you find my reply solved your question or issue, kindly click the 'Accept as Solution' button and vote it as helpful.
You can also learn more about ISE through our live Ask the Experts (ATXs) session. Check out Cisco ATXs Resources [https://community.cisco.com/t5/security-knowledge-base/cisco-endpoint-security-ask-the-experts-resources/ta-p/4394492] to view the latest schedule for upcoming sessions, as well as the useful references, e.g. online guides, FAQs.
-------------------------------------------------------------