user-id

see https://support.google.com/tagmanager/answer/4565987
is your tag manager compatible with this feature?

In the new google tag manager I can use fieldname=userID, value= {{uid}}

will that work together with your plugin settings: Basic Data > Visitors > Logged in user ID ?

https://ww.wp.xz.cn/plugins/duracelltomi-google-tag-manager/