Melt 1 Tbsp butter in a saucepan over medium heat. Add 1-1/2 Tbsp flour. Cook over medium heat for 1-2 minutes, stirring constantly.
Whisk in remaining flour (1 Tbsp) and remaining ingredients (Worcestershire sauce, garlic powder, onion powder, salt, and pepper).
If meatballs are frozen, add them to a saucepan with 1 Tbsp melted butter, and cook (stirring every 30 seconds) over medium heat for 3-5 minutes.
Add meatballs to cream sauce, and cook, stirring constantly, until meatballs are covered in sauce.
To make homemade Swedish meatballs, see my recipe here: https://nashvillewife.com/homemade-swedish-meatballs/