Prepare the keto spaghetti sauce according to its recipe or package directions.
If using ground meat, add the ground beef or ground chicken to the sauce and simmer until thickened, about 20 minutes.
Bring a large pot of salted water to a boil, then add the keto spaghetti and cook 8–10 minutes until al dente, or follow package timing if different.
Drain the pasta in a colander and return to the pot or place into serving bowls.
Toss the drained spaghetti with the sauce, or top individual bowls with the sauce. Sprinkle with Parmesan cheese to serve.