IIRC, it's in the far forward, outer corner of the little 'box' you're groping in. It may be worth removing the tyre one time so you can see what's what. Then groping will be simple in the future.
Removing it is pretty easy. Getting it back in place by feel alone, having no previous visual reference, can be challenging. Some are much better at this than others.
Removing it is pretty easy. Getting it back in place by feel alone, having no previous visual reference, can be challenging. Some are much better at this than others.