Redirect to first child

[KonradHEXANT]

It's something I used to use in other builders as a special template for the parent page. This is especially useful if you have like website section "about us" (just empty page to keep URL nice), but finally, the proper pages are children of that: "company", "team", etc. So finally you got "/about-us/company"... but if anyone temper with URL and leaves it as /about-us/ it receives a blank page, so redirect is useful.

The code I was using until now was OK, but it doesn't work with the Oxygen template. Creating a new template with a PHP code block only generates only errors.
Is there an option to do such thing in Oxygen?