You can puree them and make jam. Or juice them and make jelly.
Iirc, that’s the old school canning method for preservation
Edit: here is a good set of instructions for jelly. The difference between jam and jelly is that jam uses whole fruit that’s been puréed.
(At least, that’s the distinction in the US. I’m aware euro, jelly=jello in some places… jello sets harder…)
I would suggest straining it for jelly instead. You tend to get a better texture that way, and you can usually find a canning section in most grocery stores with mason jars, rings and lids. Everything gets sterilized in a pressure cooker (or boiled) to help it last. If you don’t want to use the ring-leads, the parrafin wax that’s also right there can be used- melt in a double boiler and pour a 1/2 on top.
(or… if you don’t use gas, just a pan, is fine. To quote my grandma, “It is wax. You can make candles out it. Or a house fire.” She taught me most of what I know about canning)