@Ondřej Melichar I’m not sure, but you may have to. When you stop your Prefect Server, the GraphQL API is no longer reachable. Your agents need the GraphQL API to be reachable at all times, since they regularly query it to poll for new flow runs.
Overall, the Server and agents are supposed to be running 24/7. If you have difficulties setting this up, you can sign up for Prefect Cloud - it’s much easier to get started, it’s always on, and you get 10000 free task runs for free each month, which is more than enough to get started.