Unable to add Application Links

[Niranjan Deshpande]

I have got the integration between bitbucket cloud and jira server (local install) working.

Since there is no feature in JIRA which allows a specific bitbucket repository to be mapped with a specific JIRA project, I was trying to use Project links (mentioned as a comment on this [JRASERVER-38738] Ability to link a JIRA project to a specific repository (or group of repositories) - Create and track feature requests for Atlassian products.)

While doing so, I am getting this error. I am seeing this error in the browser's developer console:

Access to XMLHttpRequest at 'https://bitbucket.org/<my-bitbucket-repo>/rest/applinks/3.0/manifest.json?_=1625095162648' from origin 'http://localhost:8080' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
batch.js?agile_global_admin_condition=true&healthcheck-resources=true&jag=true&jaguser=true&locale=en-US:12123

GET https://bitbucket.org/<my-bitbucket-repo>/rest/applinks/3.0/manifest.json?_=1625095162648 net::ERR_FAILED

Corresponding error on JIRA is: 

No response was received from the URL you entered - it may not be valid. Please fix the URL below, if needed, and click Continue.

Are there any security related settings that need to be configured? There are some browser plugins which allow this but it has not been effective. So I am looking for help to understand this problem better - what is going wrong here? What is the proper way of resolving this error? As I might need to use same security settings once I move this integration to the JIRA prod. server.