PORT (3000), HOST (127.0.0.1) and PATH are set by the panel. How the files load
.env
Shared by build and runtime · /home/api-example-com/htdocs/api.example.com/.env
.env.build
Build only · /home/api-example-com/htdocs/api.example.com/.env.build
.env.runtime
Runtime only · /home/api-example-com/htdocs/api.example.com/.env.runtime
Service overrides
Advanced runtime variables. These override the project files and are not passed to builds. Existing panel variables are preserved here.