Now I have backend that use websocket server. I am depoying it on back4app but when run "yarn run" command in deploying process on back4app, following error occured.
CMD [ "yarn", "start" ]
2023-06-07T17:20:56.002Z INFO No files changed in this command, skipping snapshotting.
2023-06-07T17:21:00.000Z INFO Pushed registry.containers.back4app.com/back4app2-ebfe0731-023e-4a58-b5cb-fa424c74f5e8/cache@sha256:bc0cd2735ce537b1ff2f4ca118410561931fa5196788e7234b3271220fd51c91
2023-06-07T17:21:00.001Z INFO Pushing image to registry.containers.back4app.com/back4app2-ebfe0731-023e-4a58-b5cb-fa424c74f5e8:3fece98e-2d0e-46bd-9ac2-46e3e6ba80cd
2023-06-07T17:21:07.000Z INFO Pushed registry.containers.back4app.com/back4app2-ebfe0731-023e-4a58-b5cb-fa424c74f5e8@sha256:70462bcd4f57ce485ae70a30e2ae93eece99db520a7244af69fd7a5852211eaa
2023-06-07T17:21:08.711Z SYSTEM LAUNCHING CONTAINER...
2023-06-07T17:21:22.796Z SYSTEM CHECKING HEALTH...
2023-06-07T17:21:22.797Z SYSTEM trying to hit the 3000 port using http
2023-06-07T17:21:22.802Z SYSTEM it looks that no process is listening to the 3000 port using http
2023-06-07T17:21:22.807Z SYSTEM trying again in 1s
2023-06-07T17:21:23.807Z SYSTEM trying to hit the 3000 port using http
2023-06-07T17:21:23.810Z SYSTEM it looks that no process is listening to the 3000 port using http
2023-06-07T17:21:23.812Z SYSTEM trying again in 2s
I change backend port as 3000 but still error exists. This is first deploy for me. I have deployed this backend server on cloud yet.