Gmail API watch request not working properly

There are many post on this same topic but still there is no exact solution to solve this issue.

even in the google API below link, there is a option to test the API https://developers.google.com/gmail/api/v1/reference/users/watch

This API throws a error like Invalid Topic Name does not match but I have created the topic in the pub sub and I have published the message on it, that topic works fine but then also I am receiving below error. I am receiving 400 error

{ "error": {"errors": [{
"domain": "global",
"reason": "invalidArgument",
"message": "Invalid topicName does not match projects/google.com:apisexplorerconsole/topics/*"   }  ],"code": 400,"message":"Invalid topicName does not match projects/google.com:apisexplorerconsole/topics/*" }}

I have tried to call this API in client side, like below

gapi.client.gmail.users.watch({
    'userId': 'me',
     "topicName": "projects/fast-metric-178608/topics/Test" 
  }).then(function (response) { 
        console.log(response) 
  });

Below is output , i am receiving 403 error

{ "error": { "errors": [{
"domain": "global",
"reason": "forbidden",
"message": "Error sending test message to Cloud PubSub projects/fast-metric-178608/topics/Test : User not authorized to perform this action."}  ],"code": 403,  "message": "Error sending test message to Cloud PubSub projects/fast-metric-178608/topics/Test : User not authorized to perform this action." }}