We are a business that rents and sells commercial industrial cleaning equipment. Three weeks ago, we signed a contract with a new agency to manage our digital ads for a monthly retainer of 25.000 TL. During the onboarding process, their tech specialist requested our website's Google Tag Manager ID and full administrator access to the dashboard.
We manage our website's source code and servers internally. The agency states this access is mandatory to set up conversion pixels, Google ad tags, and form submission tracking. However, our technical team is cautious since code can be directly injected into the site via GTM.
Does sharing the Google Tag Manager ID with the agency create a security vulnerability on its own? Furthermore, is there a standard, secure way to let them accurately track conversions without granting full admin rights to the container?