Plugin Problem in desktop modeler

I downloaded modeler from GitHub - camunda/camunda-modeler: An integrated modeling solution for BPMN, DMN and Forms based on bpmn.io. on windows.
I added a plugin to resources/plugins/ .
I can see “plugin” menu in “dev” mode when I run “npm run dev”.
But I can’t see “plugin” menu in “build” mode when I run “npm run build”.

What should I do to access plugin in the final product?