There is no adjustment apart from replacing the bushes in the cross member and the drag links
The 100 series are cheap mowers built down to a price for JD by AYP.
IF you want to have adjustable toe in/out then cut the end off the drag links ( both if you like ) thread it then buy a pair of tie rod ends.
They are not cheap which is why they were not fitted in the first place.
Almost no domestic level mowers have adjustable toe in and a lot do not even have a proper joint.
The market gets what the market will pay for.
The market will not pay for adjustable steering so the makers do not fit it.