url for links to internal pages/between pages

Editing links from product pages.  When I initially create a link it will accept the entire url of the page I am linking to. I've changed the name/url of the page I am linking to so I am going back to all the product pages to update the link to page.  Upon edit, the url field will not accept the full url including the root but only the page.  Example https://journeycamera.com/sure-grip-and-leather-straps was accepted when the link with originally created.  When I changed the page name to https://journeycamera.com/sure-grip-and-leather-camera-straps (adding camera) only the /sure-grip-and-leather-camera-straps would allow an update.  What is the proper way to create links to other pages? Include the root or just the page leaving the root out?