In the details pane for the flow you can add additional Owners, people who can edit the flow, or run only users, people who can run the flow. To see the flow users need to be in one of these two categories.
Since this is a selected item trigger there is one other possibility. in the run only users panel you can add the list itself as a run only user. Doing that will give anyone with access to the list the ability to run the flow.
