There is currently no supported way to delegate Flow Action authoring within a scoped application without granting the global flow_designer/action_designer roles. Since these roles are not scope-restricted, it effectively provides elevated (as you can become admin easily using a global system flow) access across the platform, which is why it cannot be safely assigned to citizen developers.
In order to keep our citizen developers from using other external tools allowing them granular control of REST Action development and script action snippet development with the same freedom Flow or SubFlow authoring allows, cross-scope access would still need to be approved etc.
Please consider voting for this idea in the Idea portal for allowing delegated scope developers to also be able to work with Flow Actions. Something which today is not possible without high flow_designer/action_designer admin equivalent which we don't want to grant citizen developers.
https://support.servicenow.com/ideas?id=view_idea&sysparm_idea_id=d7001549936c4390c2513f986cba104d&…
