This Red is Blood Chapter 76

There are two sources of tickets for outsiders.

One is an "inviter" like Wesley Si, who is suddenly pulled into a prison train without warning one day, stamps a ticket on his arm, and begins to escape.

There is also a category of "ticket holders" who are given tickets and then forcibly pulled into the prison train.

After each outsider travels through the three worlds, he will have the opportunity to send a ticket to someone he knows through the conductor.

Usually, just look for something like a display on the return train to see a detailed description of the relevant content.