We need to update the Shipping Tracking Number that we enter on the Admin page on to another website. Is it advisable to change the Admin page and add a button which will call a function or design a new page to update the shipping and not disturb the Admin Pages
If you add any code to an existing page it will get overwritten by updaters so isn't really advisable. If there is no alternative, document and comment the changes carefully so they can be popped back in after updating.