Hello,
hope that helps:
# How n8n should be made available. Gets by default also used to create the base of the webhook URL.
N8N_HOST="n8n.example.com"
N8N_PORT=443
N8N_PROTOCOL="https"
# If the Webhook URL is different because for example there is a reverse proxy in front of it and n8n does
# use port 4000 but is reachable from the outside via 443 it can be overwritten with:
WEBHOOK_TUNNEL_URL="https://n8n.example.com/"
# This URL gets used in the Frontend to tell it where the backend can be found
VUE_APP_URL_BASE_API="https://n8n.example.com/"
So the error you describe sounds to me like that either the environment variable VUE_APP_URL_BASE_API is not set correctly or n8n is not reachable.
Can you tell me what happens when you click on the “+” on the right side to create a node. Does the list contain any nodes?