Can't exclude categories on FullCalendar / WP Calendar

I am using WP Calendar to add events to my WEBsite, and using the Full Calendar option to display a graphical calendar on a particular page.

I want to exclude (or include) certain event categories from that Graphical calendar, but I can’t make it work using the HTML code I saw in the documentation.

I tried the following code on the page for the graphical calendar:
{events_calendar; categories=”x,y”} where x and y are the categories. I tried using the category name and the slug. I also tried {events_calendar; event_categories=”x,y”} but that did not work either.

Can someone help me? Thanks.