You can either use the session-wide link, persistent links, or single-use links.

Session-wide link

If it is impractical to distribute distinct URLs to each participant, you can give the following start URL to all 13 participants.

https://floating-sierra-61355.herokuapp.com/join/n8hyrwv0hm/

Note: unlike the other link modes, this does not prevent the same person from playing twice.

Persistent links

If you want to give your participants permanent links that don't change, you should create your session in a room.

Single-use links

Below are single-use links, which you can distribute to your participants. Each link has a unique code for the participant.

P1	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/idp3ayw0
P2	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/w2fsld4w
P3	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/45lyb1sh
P4	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/4cmserwj
P5	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/dtgpe3b1
P6	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/oai40hjk
P7	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/kw8jj26p
P8	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/c9udo7r6
P9	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/puww2604
P10	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/70rswwyf
P11	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/nisee0er
P12	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/qlv8dcl0
P13	https://floating-sierra-61355.herokuapp.com/InitializeParticipant/v8h0krf4