Preheat oven to 375°F (190°C). Line a loaf pan or baking sheet with parchment.
In a large bowl, combine ground beef, almond flour, eggs, onion, garlic, Worcestershire, smoked paprika, salt, and pepper. Mix just until combined.
Shape into a loaf and place on the prepared pan.
Whisk together sugar-free ketchup, apple cider vinegar, and brown sugar substitute for the glaze.
Brush half the glaze over the meatloaf. Bake 40 minutes.
Brush with remaining glaze and bake 15–20 minutes more, until internal temperature reaches 160°F.
Rest 10 minutes before slicing.