Dataverse Files in PowerBI report

I have a dataverse upldated via an power app. Staff enter the date they have completed their training and attach approriate certificates.

In Power BI Managers want to be able to access these files via a link. I have done this before with sharepoint but cant work out how to build the link for dataverse.

I have the GUID of the file from the fileattachment table and the filename from the same.

I assume the url is someting like  https://<orgUrl>/api/data/v9.1/<entity-type(id)>/<image-attribute-name>/$value as this is for images, but I have files (pdfs, docs etc...) so how do I build an equivalient URL

Related is there a way to get the orgURL dynamically? I dont want to hard code as the reports will move between Dev, UAT and Live and I ideally dont want to manually update.

Thanks in advance.