Attachments Mandatory on Employee Resignation

Summary:

Content (required):

We would like to make the attachments field when employees are submitting the Resignation . I Tried to use HCM Experience Studio select Resignation and tried to add new Rule , but in Comments and attachment section the Attachment Required option is not visible, any one can have solution , Please find the screen shot

Thanks in advance

Version (include the version you are using, if applicable):

23C

Code Snippet (add any code snippets that support your topic, if applicable):