To Issue and Return the books, go to Library > Issue Return. Here search the student by entering Member Id, Library Card No or Admission No after that click on Issue Return icon from the Action column, this will redirect you in the Issue/Return book page.
To issue book, go to the Issue Book Section and then select Book (as you select the book the available quantity of that book will show in the bottom of the select box) and Return Date then click on the Save button. The issued book will be show in Book Issued section.
To return Issued book, go to Book Issued section and then click on Return icon present in the Action column, at click of this icon it will ask you to confirm, after your confirmation book will be returned.