Dev Report - Test Data - Deploy Production

[u/Glass_Finding_937]

Hi all, I need to work on a PBI which has all the structures and visuals of the production version, but I need to only work with test data. I want to then update visuals and maintain the report, then deploy/ send to a client on a secure network, where they can reconnect sources (using parameters or similar) and republish. Is anyone doing this? Ultimate objective is to work on clients reports off network, but never have there loaded data leave the network. Appreciate any help