Here are the requirements for getting visitor ID service enabled:https://marketing.adobe.com/resources/help/en_US/mcvid/mcvid_requirements.html

How can I get enabled/use the visitor ID service?

No, this is not currently a feature that is available. More info about other options here.

Can I restrict DTM access based on IP address?

 Hey Daniel, Did you see Alexis's update & questions? Please let us know if you if you were able to resolve your issue or if you need more help.~Laurel

Hello Theirry, This particular forum is dedicated to Adobe Marketing Cloud, specifically Activation - Dynamic Tag Management. Unfortunately I have limited knowledge of the Creative Cloud. The best to post questions about Adobe Photoshop to their specific forum, which is located here https://forums.a...

Hello,Sorry for the delay, you'll find more info about the Marketing Cloud's integration and how to sign up for a demo here http://www.adobe.com/marketing-cloud.htmlLet us know if there's anything else we can help with!-Laurel

Hello, Sorry for the delay, which product would you like a demo of? Please let me know so we can assist. -Laurel

There are a couple of common issues that can prevent you from successfully inviting a new user to DTM, read about how to troubleshoot them here: https://helpx.adobe.com/dtm/kb/troubleshooting---why-am-i-unable-to-invite-users-to-dtm-.html

Why am I unable to invite users to DTM?