title: Authenticating on behalf of a user from durable functions using MSAL
body: <p>We have a suite of dotnet 6 azure functions (v4) which serve data to an single page client application.</p>
  <p>The client authenticates with our api on behalf of the signed in user. These endpoints go on to call a downstream dependency also on behalf of the user using the Microsoft.Identity.Web library and a distributed sql token cache.</p>
  <p>In addition to these apis, we have a durable function, which is triggered by one of our api functions. The resulting orchestrator spins up to process a queue of imports, which can take up to 30 minutes to process. These imports also require interaction with a downstream api on behalf of the user who kicked off the durable function.</p>
  <p>The issue I'm facing presently is how to fetch a bearer token for these downstream outbound requests once the durable function takes over.</p>
  <p>FYI, the outgoing http requests requiring on-behalf-of authentication are a few layers of abstraction away from the orchestrator (i.e. ochestrator =&gt; activity function =&gt; service =&gt; client). We're not using DurableHttpRequest for these requests.</p>
  <p>Any help with this would be greatly appreciated!</p>