In ADF, a variable called Datetime was specified to be entered and executed in a workflow called Parent using Web Activity.

There is a Child Workflow (two-step workflow) in Parent Workflow, and Datetime variables are available in Parent Workflow, but Datetime variables are not available in Child Workflow.

In my opinion, I expected the variable to be inherited from Parent to Child, but it was not. How can I apply it to Child Workflow the same as Parent?