Letter by Letter - Display faceset

I do not know how to set the picture of the character's face on the side/in the message box, for the life of me. I have Letter by Letter - SITA.

I see the section in the script where it says face sets, but I don't know how to do it. -noob-

if you can find CCOA's UMS, it's a simple feature to activate.

or rather, you'd use the face command (originally thought the question was about LbL for a second there)

Thank you! Though I read something earlier about messaging systems clashing? Would LbL clash with UMS? or ToA?