How to Rebind the Report's Datasource Before Deploying to a Different Customer Without PBI Desktop

I am following a multi tenant approach to PowerBI, where each customer will have their own workspace. In each workspace, there will be an identical set of semantic models and reports. 

Using the PowerBI API, I was able to achieve this easily with the semantic models. For each one: I deploy the .pbix file, update the parameters, and bind it to a gateway. For reports however, I am struggling to do so. The issue seems to be that the reports are published with the dataset connection. So for example, when developing a report I used customer A which points to a semantic model in customer A's workspace. 

Once satisfied, I publish the report to customer A's workspace and can then go download the .pbix file. However when I want to deploy .pbix file to customer B, it fails because customer B cannot access the datasource that is in customer A's workspace & provides the following error message:

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