Floor anchor point for a rear-facing infant seat

[glebvk]

I have Combi Cocoro infant seat with a tether to be anchored to the floor.
Like this:

or this:

Where can I do that in a M3?

I'm considering passing a webbing loop under black crossbars:

but am worried if the strain might brake the latches that lock the cushion.

 

[Nogasmn]

In the US a floor attachment point is not required for a rear facing seat, first time I am seeing something like this. Also with how tight you fasten down a child's seat there is no risk that the seat would rotate back.