Can you verify the service has started?
Sorry, I'm completely new to Ignition. so what do you mean by service has started? if you mean that the service work at "localhost:8088" then yes, it's working
What operating system are you running Ignition on?
If you're running it on windows you can go to the services panel to see if the Ignition service is running.
Win + R
Services.msc and press enter
Scroll down to find a service called "Ignition" and make sure that's running.
Instructions vary for other operating systems.
I checked it, and it's running. I even made sure it has an exception in the firewall.
Did you tried restarting the service? Did you perhaps change the port configuration in the gateway?
I didn't change anything in the configuration