How can we make project field mandatory based selected project number at Distribution level

Hi All,

We have a requirement that, based on the project number selected at the Invoice Distribution level, the line-level project number should be mandatory.

For example, if a project value other than the default is selected, the line-level project number field should be mandatory. If the default project value is selected, the line-level project number should not be mandatory.

Appreciate for your support.

Thank You.