Unable to mount volume in azure app service?

I am trying to deploy a Node SDK on azure app service through docker container. In my sdk, I have mounted a connection file & written a docker-compose for this. But when I deploy it by azure I get below error.

InnerException: Docker.DotNet.DockerApiException, Docker API responded
with status code=InternalServerError, response={“message”:”invalid
volume specification: ‘:/usr/src/app/connection.json'”}

docker-compose.yml

version: '2'

services:
  node:
    container_name: node
    image: dhiraj1990/node-app:latest
    command: [ "npm", "start" ]
    ports:
      - "3000:3000"
    volumes:
      - ${WEBAPP_STORAGE_HOME}/site/wwwroot/connection.json:/usr/src/app/connection.json

connection.json is present at this path /site/wwwroot.

Dockerfile

FROM node:8

# Create app directory
WORKDIR /usr/src/app

# Install app dependencies
# A wildcard is used to ensure both package.json AND package-lock.json are copied
# where available ([email protected]+)
COPY package*.json ./

RUN npm install
# If you are building your code for production
# RUN npm ci --only=production

# Bundle app source
COPY . .

EXPOSE 3000

Please tell me what is the issue ?

Source: StackOverflow