Xbox Ambassador Tag Line

You'll need to complete a getting started mission that includes the forum quizzes. That will also give you access to the Ambassador forum where Ambassador issues should be posted. If you did not complete the quizzes before April 1, there is a known bug
with giving that tag and you will have to wait for that to be fixed before you receive the tag. If you need further Ambassador related assistance before then, you'll want to reach out to a CM or use the Discord server.

You have the Ambassador tag. Keep in mind the Insider tag is for Windows Insider not Xbox Insiders since Xbox Insiders use Reddit.

I have found this:

In order to become an
Xbox Ambassador, you must meet these three requirements:

1. Be at least 17 years old.
2. Have an Xbox Gamerscore of 1500 or higher.
3. Have no
   previous enforcement actions on your Xbox Live account.

The big change is you no longer need to have an
Xbox Live Gold account. Anyone with an
Xbox Live account (Gold or Silver) can be Xbox Ambassadors. Once you meet the requirements and sign up, you will be greeted with a welcome video (see below) that quickly explains the highlights of the program and sets you on your way to the very first welcome
mission.

You can talk about being an Xbox Ambassador on any social media platform you choose;
Twitter,

Instagram, or https://www.onmsft.com/tags/youtube. Be sure to include #XboxAmbassadors so that fellow Ambassadors can reach out to you to connect. The goal of being an Xbox Ambassador is to get the word out an recruit more gamers to become Xbox Ambassadors too.

Please remember to keep anything Ambasador related in the Ambassador forum. To access the forum, you'll need the Ambassador tag in the forums. If you've joined the program, contact Ambassador staff to see about getting your tag added.

You'll want to post over at the Community Center to see about having it added.