Once you have created your account, you have to generate a personal access token (PAT). This will be required, primarily, during the configuration of the local agent and to be able to trigger the pipeline builds from remote (via REST calls). Anywhere within your Azure DevOps account select your user profile in the upper right hand corner

and select the Personal access tokens option.

Add a new token, give it a new, define the duration it will be valid and define the access scope. For the latter, the Full Access option will be okay to get started. In a real-life situation, you will, of course, make sure to limit the access to resources in your project as much as possible.

And create the token.

Warning

Make sure to save a copy of the PAT generated for you. It will not be possible to retrieve the token at a later time. If you loose the token, you need to re-generate a new token.

Create authorization header for the PAT

Within a rest call, the PAT needs to be passed in encrypted form via the authorization header of the http request. While there are several ways, to get the encrypted version, one way is by using a REST request testing tool like Google's Advanced Rest Client (ARC). In the tool, create an authorization header for any request and use the pencil button to provide the credentials you would like to be encrypted. For you Azure DevOps PAT the user id and password to use are both the PAT.