The standard URL of a ticket in agent panel looks like this:
https://your.domain.com/agent/#Conversation;id=2a37d186
2a37d186 is the ticket id. If you don't know the id, but you know the ticket code e.g. MIE-ZXRXT-212 this is the correct URL that will open the correct ticket:
https://your.domain.com/agent/#Conversation;code=MIE-ZXRXT-212