Serverless: Your serverless.yml has an invalid value with key: "Ref" - dialogflow-es

Question

While installing serverless with following command
sls plugin install -n serverless-alexa-skills --stage dev
I am getting an error like Your serverless.yml has an invalid value with key: "Ref"
The following is my sample serverless.yml file
plugins:
- serverless-webpack
- serverless-s3-sync
- serverless-plugin-git-variables
- serverless-alexa-skills
functions: ${file(./deploy/${opt:stage}.yml):functions}
resources: ${file(./deploy/${opt:stage}.yml):resources}
custom: ${file(./deploy/${opt:stage}.yml):custom}
outputs:
DialogflowFunctionArn:
Value:
Ref:
Got a block here. can some one help me here.

Answer 1

Ref is a Cloudformation intrinsic function. It needs to reference a resource. The whole outputs section is also optional, use it only if you need to reference the resources from one stack in another.

Answer 2

It basically says that Ref: is expecting a value. You have defined it but not assigned any value to it. If there is no use then you should remove this part from your code:
outputs:
DialogflowFunctionArn:
Value:
Ref:

Answer 3

Ref expects to reference something, right now you are not passing it anything to reference.
So, assuming you want the ARN of DialogflowFunction and that function config looks something like this in your functions file:
DialogflowFunction:
description: get the flow
handler: src/functions/dialog-controller.flow
events:
- http:
path: '/dialog/flow'
method: get
cors: true
Then your ref would look something like this:
outputs:
DialogflowFunctionArn:
Value:
Ref: DialogflowFunction
Ref takes the logical id of the resource for which you want to reference, in this case that is DialogflowFunction, and will return the ARN of that resource.