Page not available error when opening external link from a web viewer

Hello, I have a problem, I have a Web Viewer, which is a directory of businesses and each business has a link to whatsapp which are several links, I solved it just like in the blocks, but not completely because if I give it back to the site it returns correctly, but if I press one more to exit it throws the error of the page not found.
thank you in advance
bloques

instead of elseif use else and then close app
and what is your webview home url? check whether it is empty
may b u used go home instead of go back

hello friend, I’m really new to this, but what I need is that from my site I can go to whatsapp links, the blocks above are for the return button of the mobile to work, if you can support me with a screenshot of how it would look, I’ll be grateful

didnt answered

blocks