Update Request Button missing, very N0Ob question

hello,

I am completing a course and we use postman to monitor and update data sent between server and client.

The current module involves Basic Authentication, however when in the module they select the Basic Auth option from the drop down menu in postman, enter the Username and Password and click “Update Request”, there is no “Update Request” button.

Can anyone help as to where this button is or if it was replaced and by what?