Yes, it involves placeholder. The head placeholder.
Create placeholder anywhere on your page and give it a "<head>" name.
In the placeholder code field enter your meta tag.
The above from Covoxer several years ago.

A placeholder is a simple rectangle. Select the rectangle, open the Website Properties > Placeholder section and insert the meta tag code in the HEAD section.

Select the rectangle then click the yellow nametag icon and add the name <head>

The placeholder will not be visible but will automatically insert the code into the HTML script.