Output todays date

Is there any easy way to output todays date on a page?
I am still new to Grav. It would be easy to just do it via custom PHP, but as far as I understood, I can't just insert php into a page? Why is that?

https://twig.symfony.com/doc/2.x/filters/date.html

{{ "now"|date("m/d/Y") }}

Thanks for your answer.
I just have to insert this as page content? I tried it, but it doesn't show the date, but just shows up as the same source code.

https://learn.getgrav.org/16/cookbook/twig-recipes

when using within pages make sure you add following configuration to the page header:

twig_first: true
process:
    twig: true