Docker / Action server error: Failed to run custom action / Couldn't connect to the server

HI Jonathan!! I wanted to have a further explanation! I ran into your same problem, I also opened a thread about it: Custom action Don't Work!. since I’m not very practical, in my case what should I write in place of localhost ?? you wrote this: url: “http: // rasa4_action-server_1: 5055 / webhook”. where can I get the information to insert in the string? thank you very much!!