From inside a Ticket, you can do the following things:

1. Create a new contact directly in the ticket, by clicking the Requester address at the top below the subject line, followed by Create new contact. If you want to save the contact information to an existing profile, you choose Add to existing contact.

2. Go directly to the sender's customer card (if the contact is saved), by clicking the Requester address at the top, below the subject line, followed by Go to profile.

You can also access the sender's customer card by clicking the contact's name under Contacts in the menu on the right.

3. Add multiple people as contacts in a ticket, if there is more than one main contact in the ticket. To do this, click + Add agent under Contacts in the menu on the right.

Read more about the possibilities in Contacts in the following article: What can I do in the Contacts tab?