Unable to render this definition (Please indicate a valid Swagger or OpenAPI version field.)

[shakalpatle]

Hi Team, I have hosted Dependency Track on a VM using docker environment and when trying to get the Dependency Track API using Swagger UI chrome extension according to the documentation using " http://{hostname}:{port}/api/swagger.json ". But I am getting the error as shown in the attached screenshot. Unable to render this definition.
The provided definition does not specify a valid version field.
Please indicate a valid Swagger or OpenAPI version field. Supported version fields are swagger: "2.0" and those that match openapi: 3.0.n (for example, openapi: 3.0.0).

{"schemaValidationMessages":[{"level":"error","message":"Can't read from file https://{hostname}:{port}/api/swagger.json"}]}

The log doesn't show any hint. I would be glad if you 'll get me a hint about my error / misunderstanding.

Thanks a lot,
Shakal