Toyota Yaris GRMN Owner's Manual page 31

Fastening the rear center seat belt
Take out the plates, and then
pull the seat belt.
Push the plate into the buckle in
the order of plate "A" and plate
"B" until a clicking sound is
heard.
Plate "A", buckle "A"
Plate "B", buckle "B"
YARIS_GRMN_OM_Europe_OM52J40E
1-1. For safe use
Plate "A"
Buckle "A"
31
1
Plate "B"
Buckle "B"