Hi @ryankhgb
You need to go to https://www.shutterstock.com/account/developers/apps and select the App you are using with this plugin. Click the ‘…’ on the App and then click “Edit”
In the App Edit prompt, you need to set the Referrer field to match your WordPress site’s domain. For local development that might be “localhost”, or if your site is hosted at e.g. ryankhgb.com you would put “ryankhgb.com” as the Referrer.
Note if your site is available on multiple domains, you can put them as a comma separated list in the Referrer field, e.g. “localhost,ryankhgb.com”
Hope this helps!