The user who invites a new participant can link them to one or more categories. This will automatically define the participant as the user in charge of points created in the category to which he is linked.
1) Open the participants menu in the entire project
2) Click on the manage icon on the top right corner
3) Click on categories links
4) Click then on the edit icon on the top right corner of your screen, to be able to link the participant(s) of your choice to some categories. Do not forget to save your changes!