Hi @Anish ,
Good day!
As a first step please verify the domain & API key provided are valid (API key need to be taken from user → profile settings → Your API key).
Make sure to add whitelisted domain in the manifest.json
"whitelisted-domains" : [ "https://*.freshdesk.com"]
If the issue found to be not resolved, please share us the HAR logs with us to debug this further.
Thanks