Add diced tomatoes and apple to Instant Pot. Close lid, and set timer to 4 minutes on high pressure. Allow natural release of pressure for at least 10 minutes before carefully releasing remaining pressure and opening lid.
Set Instant Pot or pressure cooker to sauté and simmer the tomato mixture for about 15-20 minutes, stirring occasionally, until the apple breaks down and the liquid is reduced by about half.
Stir in the smoked paprika and lemon juice.
Ladle into glass container (or jelly jars, if you have them) and refrigerate until ready to use. It will thicken more as it cools.