Auth Error type Error : Failed to fetch

Hi all,

I implemented swagger YAML file for generating the documentation for my rest API's. I could able to generate and run my API's successfully which are not involving OAuth2 Authorization. But the API's which are about to authorized through OAuth2 authentication grant type are failing to authorize and am getting the below error of 

"Auth Error type Error: Failed to fetch".

I used the security schema inside my swagger yaml files as

OAuth2:
type: oauth2
flows:
authorizationCode:
authorizationUrl: http://localhost:9095/oauth/authorize
tokenUrl: http://localhost:9095/oauth/token
scopes:
read: Grants read access
write: Grants write access
admin: Grants access to admin operations

Please help me out in this issue and let me know why am i not able to authorize with the provided client ID , secret ,authorize URL and token URL.

Where am i Missing anything?

Thanks in advance...