You can't steam the lid tightly if you can steam it. You should cook the food before you put it in the can. Here's how to make canned apples:

Preparation materials: 500g of apples (net weight after peeling and coring), 800g of water and 70g of rock sugar?

1. Peel, core and cut the prepared apples and put them on a plate for later use.

2. Add 800g of water to the pot and 70g of prepared rock sugar.

3. After the water is boiled, add 500 grams of apple pieces and cook for a few minutes.

4. Cook the apples in sugar water and put them in a bowl for cooling.

5. After the apple in syrup is cooled, bottle it and put it in the refrigerator for sealed preservation.