How to enable manual selection of an Approver
Navigate to Module Setup by going to Settings -> System Configuration -> Module Setup.

Select the Settings option on the Cog menu of the Module.

In the Approvals section untick the "Use Auto Approval" setting.
Once saved this will allow an approver to be manually selected during the submission process.
This has to be done for each Module and saves setting just one Default Approver at the Org Unit level.
