@Manisha Goli Hi!
You can do this by using the mobileDeepLinkGenerator. So when you look at an incident record in the Agent app, then that screen should take a sys_id as a parameter.
It's been fairly long since I configured this, but I just found an article that does this step by step: https://community.servicenow.com/community?id=community_article&sys_id=5a7c69221bf03010aefc11751a4bc...
But I like the article, since it gives you the dynamic link - so either it goes to the portal or it goes to the mobile app!
Hope this helps...Please mark helpful
