In the bowl of a stand mixer, combine the yeast, sugar, and cup of warm water. Using the dough hook, stir and let mixture stand for 5 Minutes (until mixture starts to foam).
Add the melted butter and milk to the yeast mixture. Mix on low speed with the dough hook until combined.
Add ½ tsp of salt and all-purpose flour to the mixture. Using the dough hook, knead the dough for 8-10 Minutes.
Lightly oil the bottom of the Instant Pot insert. Place the dough in the insert, then flip it so the top of the dough is also lightly oiled. Using the sous vide setting, set the Instant Pot Duo-Crisp and Air Fryer to 90°F. Place the lid on top and leave the dough to rise for 30 to 45 Minutes. More on that in a minute. Allow the dough to rise for 1 hour or until it has doubled in size.
Once the dough has sufficiently risen, removed it from the Instant Pot Duo-Crisp and Air Fryer and place it onto a lightly floured surface. Divided the dough into 24 equal portions and roll each portion into a ball.
Roll out each ball with a rolling pin. Add 2 turkey pepperonis and 1 cube of mozzarella to the center of the rolled-out ball. Fold each corner of the dough over the toppings and pinch firmly to seal. Repeat this step until all the dough balls have been stuffed.
Line a baking sheet with parchment paper. Transfer stuffed balls onto the baking sheet and cover with a warm, damp towel for 10 Minutes.
In a large pot, bring 2 quarts of water to boil. Once boiling, carefully add the baking soda.
Using a slotted spoon, drop the dough balls into the boiling water for 30 seconds each. Place the dough balls back onto the baking sheet. Sprinkle with coarse salt.
Using the air fryer function, preheat Instant Pot Duo-Crisp and Air Fryer to 350°F.
Add 1/3 of the poached dough balls to the air fryer basket. Put the air fryer lid in place and air fry for 12 Minutes. *Do not turn stuffed pretzel balls halfway.
Repeat this step until all the Turkey Pizza Stuffed Pretzel Bites are cooked.
Serve warm with a side of marinara sauce for dipping. Enjoy!