Getting CORS issue and Unauthorized in plone volto

I am getting this error in console while trying login , register in plone volto

@uwaiszaki
I don't know if these can help or not
https://developer.chrome.com/apps/xhr


but I think u have some error in the permissions in JSON file.

You need to set CORS policy like this: https://github.com/plone/volto/blob/master/api/buildout.cfg#L56

Both chrome and Firefox are showing these errors in console but it's working fine in Firefox. Is there any reason for this?