Canning homemade spaghetti sauce is a lot of work, but pays off when you want a quick easy dinner without preservatives.
In order to can spaghetti sauce you MUST have a pressure canner cooker.

Basically you can make your sauce with whatever you want in it: veggies, meats, seasonings etc.  because when you process it in the pressure canner cooker it will heat it up hot enough to kill any bacteria that would cause problems.

*If you have any concerns what so ever there are USDA approved recipes you can use* (I believe those recipes can be processed in a water bath canner because the acid levels are ok if you follow the recipe exactly)

I’m a better safe than sorry type so I don’t mind processing mine in the pressure canner cooker.

For my sauce I combine:
Tomatoes
onions- sauteed in some olive oil
mushrooms
garlic
salt
Italian seasoning
tomato paste

I get it to a desired consistency/taste. The pour it into the bottles & process.  For my altitude because I’m above 5,000 feet the processing is 13lbs for 25mins.  Check your pressure canner cooker for your processing times & lbs.