Step 1
Look for your store’s «Allowed JavaScript Origins» in the Magento 2 «Amazon Payments» extension’s backend settings.
The value is unique for your store, so do no use the sample value from the screenshot.
Step 2
Open your store’s «Login with Amazon» application.
Or create an application, if you do not have it yet.
Step 3
You will find your application’s «Allowed JavaScript Origins» field in the «Web Settings» section.
Press the «Edit» button in this section, and set the value from the Step 1:
