Matter.js - How does overlapping work?

Phaser 3
1

Hello,
I have been trying to understand how the overlapping with Matter.js works for few days and I think it’s a proper time to ask for help.

I would like to create a checkpoint. It should be detected when player pass through this checkpoint.

This is what I have at this moment:

create(){
...
this.player = this.matter.add.sprite(0, 0, "player");
this.checkpoint = this.matter.add.image(1000, 800, 'checkpoint').setIgnoreGravity(true);

this.matter.overlap(this.checkpoint, this.player, this.overlapInfo);
...
}

overlapInfo(){
        console.log("Overlap");
}

I found in the documentation that:

Note that bodies can only overlap if they are in non-colliding collision groups or categories.

… so it tried with:

this.player.setCollisionGroup(-1);
this.checkpoint.setCollisionGroup(-1);

but it does nothing and I don’t see any info about what is wrong. I am looking forward for your help!

------ EDIT (SOLVED IN ANOTHER WAY) -------

I have just set the checkpoint as a sensor and checked the collision in a standard way with w “collisionstart”. It works as it should, but I would like to get to know how to make it with overlap.