Hy,
as there is no out of the box D365FO Workflow for Sales Order approval.
Beside that you build a customezied solution using X++ code or you use Power Platform to build Workflow using PowerAutomate or Logic App.
A possible flow could be:
- Use any Data event as DataEvent_SalesOrderHeaderEntity_Create or another event to indicate the Sales order is prepared
- If the event is triggered start your Power Automate or LogicApp.
- First step in PowerAutomate/LogicApp should be to set the Sales Order to "on Hold" using a predefined Hold Code (e.g. "not approved") to avoid the Sales Oder will be processed as long as the SO is not approved.
- Then start PowerAutomate/LogicApp approval with this Sales Order and assign to a person (may be supervisor, persons manager, sales responsible, ... ) or member of a predefined User Group
- When the step is approved remove the Sales Order Hold code and Sales Order should be free for further propcessing.
Just as an idea.