Thanks for the answer.
Yes, I start Strapi with: npm run develop.
But every time I change something on the code in the controller and save it, the server refreshes automatically, and I can only access the Strapi URL again after 1-2 minutes to see whether my changes were correct. I just wanted to know if there is a workaround for testing that I can see my changes immediately and not only after 1-2 minutes.