How to add adsense code using the Upfront editor

The question is available for any of the Upfront child themes.
How can a user add individual Adsense code to a page?
What I tried:
1. Embed 3rd party code - nothing happened. I just have "Enter your markup here" - but is not editable - if I click on Setting gear wheel nothing happens. The only thing working is the padding
2. Write custom code - I added the Adsense code (tried adding it into html, js) but nothing happens.

Am I doing something wrong?

Thank you