Visual Builder Cors problem with external service

Summary:

We're trying to provide an integration to an external service api. In our case we need post and patch operations. When trying to invoke the external service from Visual Builder we get the following error:

The REST API that you are connecting to doesn't seem to have Cross Origin Request sharing (CORS) for the Visual Builder domain. Try again after adding necessary CORS settings for the REST API you are connecting to.

Is it really necessary to ask the external vendor to add our Oracle HCM domain to they internal cors settings?

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