Build Docker image:
docker build --tag saleor-dashboard .Run nginx from Docker and bind it to port on your machine (in this example, it is "8080"):
docker run --publish 8080:80 --env "API_URL=<YOUR_API_URL>" saleor-dashboardEnter http://localhost:8080/ to use the dashboard.
If you want to change API_URL in runtime, you can use (assuming you have a running container named saleor-dashboard):
docker exec -it -e API_URL=NEW_URL saleor-dashboard /docker-entrypoint.d/50-replace-api-url.sh