How can get the list of project, users, Work Items from a specific process?

I need to get a list of details (Projects, Users and Work Items) for each of the Processes created in Azure DevOps. Unfortunately, I have been unable to do this using the API. Manually doing this will take a very long time. 

I have managed to obtain a list of Projects in an excel file, that I can use to reference. I was hoping to use the data for analytics purposes.

How can I accomplish this? Can I use Power BI to get the data?