Fill a small boiling water bath canner or a large pot halfway with water and bring to a boil; add the 2 jars, turn off the heat, and leave the jars in there so they stay hot.
Fill a small saucepan with water. Add rings and new (never before used) jar lids to this water. Bring to a boil then turn off the heat and let sit so they remain hot.
In a small bowl, stir together the allulose, pectin, and salt; set aside.
In a medium saucepan over medium-high heat, add the raspberries, sweet peppers, jalapeños, vinegar, lemon juice, calcium water, and butter. When the raspberries get soft, mash them thoroughly with a potato masher or a fork. Bring to a hard-rolling boil (that's a boil that you can't stir down), stirring constantly to prevent the bottom from burning.
Still stirring constantly, stir in the pectin-allulose mixture. Bring back to a hard rolling boil and boil for at least 2 minutes (stirring constantly), more if the pectin or sweetener haven't yet fully dissolved.
At this point, you can taste the jam and add more sweetener if you so desire.
Empty the hot water from the jars carefully using a jar lifter. Fill each jar with the jam, leaving ¼ inch headspace.
Put on the lids and screw on the rings. Process the jars in a boiling water bath following the directions provided by your state's FDA guidelines. Where I live, that is 10 minutes plus 1 additional minute per 1,000 feet above sea level.*
Remove from the boiling water bath and set on towels to cool. As they cool, the lids should "pop" and seal (repeat the boiling water bath process with new lids if they do not seal). These jars should be fine for about 6 months unopened and stored in a cool, dark place. They'll last longer if refrigerated unopened.
* If you do not wish to can the jars, you can store them in the fridge for about a month, give or take, or until it smells funky or starts growing fuzzy white or black stuff.