It would be locally based. You can put in your zip code here to see if there's one around you. https://www.mealsonwheelsamerica.org/find-meals
There are probably rural and remote areas that don't have the service, but there might be another option available through Senior Services, whatever your county calls it.
Not all sites would have a diabetic option. Mine does-- but it's a big city hospital kitchen doing the meals, and they have all the dietetic options.
The good thing about MoW is that it's subsidized, but you might need a doctor's RX for it. I'm sure they'd work with you if there's one near you.
Consider looking into meal services like those listed here: https://www.momsmeals.com/our-food/how-it-works/
But they are not cheap! You can probably get the ones that you can just pop into the microwave (no prep).
Do check with your local council on aging or American Diabetes Association. They'll have some good suggestions, I'm sure.
From that Mom's Meals site, which does have a diabetic option-
Self-pay Individuals:
We offer a self-pay program for those without an eligible health plan or who dont qualify for government assistance, but still want the convenience of home-delivered meals for themselves or a loved one.
This program offers nine health-condition menus with a variety of meal options. You choose every meal, every delivery. Affordable at only $7.99/meal.* Flat rate shipping fee applies.
https://www.momsmeals.com/our-food/how-it-works/