Server/Global account with Pro License

I''m trying to work out what the most cost effective way is to have a generic user for use in connection setups, etc, so that the connections are not reliant on specific actual user accounts... i.e. i don't want to have to update all data connections, and gateway settings (and FLows) everytime a user has a change of password or leaves the company. 

Is there a clean way of doing this?

I'm thinking of simply setting up a generic user which can be used for connection authentication (this would not be affected when actual users leave the company). But, what licenses would they need??! My assumption is O365 E1 (for Flow, etc), then a PBI Pro license for gateway access..... but is this correct? The generic user would not need to be able to create or read reports, i don't think.... simply for connection authentication.

Any help or guidance would be great.