Depress the button on the seat belt buckle.

Fastening the Seat Belt
Seat Belt ExtenderWheel Alignment Pre Inspection
1. Park the vehicle on a level ground, in an unloaded condition*, and with the
wheels straight forward.
*: Unloaded condition.....Fuel tank is full. Engine coolant and engine oil are
at specified level. Spare tire, jack and tools are in designated position.
2. Inspect the tire pressure.
...
If you have a flat tire
The Subaru Solterra is designed without a conventional spare wheel
and instead comes equipped with an advanced emergency tire puncture repair kit,
providing a modern and space-efficient solution for unexpected tire damage.
In the Subaru Solterra, minor punctures caused by objects such as nail ...
Brake Fluid Pressure Sensor Inspection
1. Switch the ignition to off.
2. Install the SSTs to the master cylinder (secondary side) as shown in
the figure.
NOTE:
When installing the SST (49 D043 0A0) to the master cylinder, use
a commercially available flare nut wrench (flare nut across flat 12 mm {0.47
in}).
...