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/w6t8mfb81f/

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/fq7ym95l
P2 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/6zpy86l5
P3 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/3z2vykkp
P4 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/qy1i6ytl
P5 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/vkhw4dw1
P6 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/tixogrlq
P7 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/6ggllme8
P8 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/q9ejept1
P9 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/3qhpud79
P10 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/jhubxj5y
P11 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/0ry39fia
P12 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/h122fbzz
P13 https://floating-sierra-61355.herokuapp.com/InitializeParticipant/1xscvsf1