Angular: Error occured while trying to proxy request “/api/v1/application/:id” from localhost:4200 to http://localhost:4000

This is my config.dev.json file:

{
  "/api/v1": {
    "target": "http://localhost:4000",
    "secure": false,
    "logLevel": "debug",
    "changeOrigin": true
  }
}

Error that i am facing:

Angular:
[HPM] Error occurred while trying to proxy request /api/v1/application/1e21006e-3588-4699-a7ce-1847b7c5409d from localhost:4200 to http://localhost:4000 (ECONNREFUSED) (https://nodejs.org/api/errors.html#errors_common_system_errors)

Nest Js:
Error: write EPIPE

Could anyone sugsest some solution