Populating a tag with a js alert in DTM is very simple. You just need to place the js alert into a third party tag in the 'Javascript / Third Party Tags' section of a rule. If you just want to test the tag, it's likely best to set this up in a page load rule so no on-page action is needed to trigger the rule fire.
Here's a few links that may provide some additional context if needed:
Populating a tag with a js alert in DTM is very simple. You just need to place the js alert into a third party tag in the 'Javascript / Third Party Tags' section of a rule. If you just want to test the tag, it's likely best to set this up in a page load rule so no on-page action is needed to trigger the rule fire.
Here's a few links that may provide some additional context if needed:
Using console.log() for testing can be a more efficient method, since you don't have to worry about any the code being interrupted while the browser waits on the alert popup.
In case the console is not open, you can use the built-in DTM function _satellite.notify('message',1) as well. It provides the additional capability of handling multiple error levels.
