How can I modify some code lines for "Google Tag Manager" in the theme template?

Sorry! I have "generatepress_child" instalated

Alternative to Child Theme templates is to use the GP Hook Element:

https://docs.generatepress.com/article/hooks-element-overview/

You can add the first GTM code to a WP_head hook and second code to the before_header hook.

Many thanks David for this information,

if I need to script for all pages I do it with the HOOKS?

Thanks,

Hooks are the easiest way to go, in the Hook Element > Display Rules you can select Entire Site. You can also Exclude the script for different posts / pages / templates and User Rules - such as User Role, so Admins don't trigger events for example.

Thank very much... David.

the email platform does not detect the code.
I created the element in 2 different ways:

FIRST: Choose Element Type:
as HEADER with "entire site"

SECOND: Choose Element Type:
as HOOK with "entire site"

But don't work you can help me for solve it...please.

Many thanks in advance!

They both need to be added to Hooks. So create a new hook for each of them, both will have the display rules for the entire site.

First code - select Hook: wp_head
Second code - select Hook: before_header

Hi David.... It was solved.... Work very well!!!
Was problem that email marketing platform.

Many thinks
Kind regards!

Awesome - glad you got it resolved :)