Connection references are a powerful additional tool that allow individual actions to execute against a different account to the one running the flow. By default, connection references are created in the name of the person creating the flow. However, they can be changed to other users, service accounts or service principals.
To add or change a connection reference, click on the elipses of an action, and select ‘Change connection’.
Irrespective, of the connection references used for individual actions, for instant flows the user who triggers the flow will need to have access to, and be licensed for, any data sources, even though the records made in those data sources are made in the name of the connection reference.