Switch from AdSense to manual ads.txt

I’m stuck on the Configure GTM section of Integrate Google Tag Manager with Google Analytics . The GTM UI doesn’t seem to have anyplace for me to specify the Measurement ID. When I publish, I get errors:

Validate Workspace

The workspace has the following errors:

Type Location Description
Unknown variable name Google Tag Configuration Settings Unknown variable “DL-page-title” found in another variable. Edit the variable and remove the reference to the unknown variable.
Unknown variable name Google Tag Configuration Settings Unknown variable “DL-page-url” found in another variable. Edit the variable and remove the reference to the unknown variable.
Unknown variable name Google Tag Configuration Settings Unknown variable “userID” found in another variable. Edit the variable and remove the reference to the unknown variable.