Add the Field Required Validator to the “Send for Approval” transition.
Select the Approvers field and configure an error message, if necessary.
Save the validator.
Validator Scope
Check the Ignore Scope option if the validation should only occur in certain cases. Examples include if the issue is of a certain issue type, has certain field values, or more generally satisfies an arbitrary Jira expression.
Use case
A typical use of this workflow validator is to validate that the field of the issue has a value during the transition. Consider a use case where you want to check that the “Approvers” field is not empty when sending the ticket for approvals. To configure this: