For Drupal 9 (and also Drupal 8) there is a new module (COOKiES https://www.drupal.org/project/cookies) that supports the modules "Google Analytics" and "Google Tag Manager" (and more). May be that’s it what you are looking for.

There is a new module for Drupal 8 and 9: COOKiES. It supports the modules Google Analytics and Google Tag Manager (and more). Maybe that's what you are looking for.

COOKiES

User consent management module for Drupal 8 and 9.

The module enables existing third-party-integration modules continued to be used in compliance with the GDPR (of course without manipulating their code). It solves the basic problem that when using third-party-integration modules, the user must agree to the use of cookies (according to GDPR) before they are installed.

IMPORTANT: No liability is assumed regarding compliance with the GDPR.

The COOKiES module provides (with the Library Cookies JSR) a fully configurable user interface for user decisions. It also supports out-of-the-box some key third-party integration modules (especially those included in the Thunder distribution):

• Google Analytics module
• Google Tag Manager
• Video embed, core:media module
• Twitter media module
• Instagram media module