[Koha] Regarding Notices in 3.8

Hi koha, I am using koha 3.8. and started notices section in koha. The problem i am facing is when i edit the checkout noitce some of the fields are not reflecting in the output mail such as <<issues.date_due>> <<issues.returndate>> but the fields such as <<biblio.title>> <<biblio.author>> is reflecting in the output mail. *The sample output mail for checkout is as below:* The following items have been checked out: Flora Of British India by Hooner, J B, Due Date: Any suggesstions regarding this problem. Thanks in advance.