Before I had posted here, I found the hooks in the appearance section. They showed up as GP hooks. That’s where I entered all the code.
But when I read your reply to my questions, I checked and realized that I did not have the ‘elements’ activated. So I activated it, and now the GP hooks link doesn’t show up anymore in the appearance section, but the elements link shows up instead.
Now I can do what you suggest with the google tags manager. However my problem is that now, with the hooks element activated, I don’t see all my previous code in the hooks boxes anymore from the time when I did not do it via the ‘elements’, but via the GP hooks link. All that code seems to have disappeared. How can I access it again?
When I deactivate ‘elements, then GP hooks shows up again along with all my tracking code. But with ‘elements’ activated, my hooks with their code disappear on me. What should I do about that?