Allowing individual requests inside a scenario can be a flexible way of approving urgent headcount requests in advance of finalizing your headcount planning scenario.

To enable, ensure the option 'Allow individual requests inside scenario' is turned on in the Scenario section within the user permissions for whomever may need to make such requests (available in Settings>User Roles>Role Name), as pictured below.

Then, if you go to the changes tab of your scenario, anyone with that permission can select the checkbox next to a draft headcount to trigger manual approvals (or approve if they are an admin).