title: Multi-repository throwing TF401019 on checkout
body: <p>I'm trying to checkout a different repository in my pipeline.</p>
  <p>These would be the full URLs, so both repositories live in the same Azure DevOps:</p>
  <p><a href="https://dev.azure.com/company/Services/_git/mylocal" rel="nofollow noreferrer">https://dev.azure.com/company/Services/_git/mylocal</a></p>
  <p><a href="https://dev.azure.com/company/OtherServices/_git/another" rel="nofollow noreferrer">https://dev.azure.com/company/OtherServices/_git/another</a></p>
  <p>I am trying to execute this in my YAML located in Services/mylocal@develop :</p>
  <pre><code>steps:
  - checkout: self
  - checkout: git://OtherServices/another@develop
  </code></pre>
  <p>From what I understand this should be simple. I have full access to both repos. Nonetheless I am getting:</p>
  <pre><code>remote: TF401019: The Git repository with name or identifier another does not exist or you do not have permissions for the operation you are attempting.
  fatal: repository 'https://dev.azure.com/company/OtherServices/_git/another' not found
  </code></pre>
  <p>I am not sure if this is even supported in Azure Pipelines. But if it is, then what am I doing wrong? Our DevOps guy says to try with a PAT, but how do you use a PAT in the checkout? I haven't found literature on this regard.</p>
  <p>What other options do I have?</p>
  <p>Thanks!</p>