Plugin on Typegoose

[perseoGI]

Hello, I am trying to add this plugin to a Typegoose class in order to have a friendship relation system on a typed server.
I have been using this plugin on JavaScript and worked well but I am having some difficulties withe Typegoose.

Don't know if you are familiar with it, if so, could you please help me with it?
I will attach code if you wish to help !