title: React App different API URLs per environment using deployment slots
body: <p>this is a question related to a CRA React app using Azure App Service and Deployment Slots.</p>
  <p>We have a Backend API that is specific to each environment, so for &quot;dev&quot; we have a specific API, and for &quot;testing&quot; we have another, basically just different URLS depending on the environment we are in.</p>
  <p>This has been solved so far by Pipelines. Building a pipeline from the &quot;dev&quot; branch in the React App, sets the REACT_APP_STAGE to &quot;dev&quot;, and we can then check inside the react app which stage we are in, and therefore change the URLs to use.</p>
  <p>The tricky part now though, is that we are planning on using deployment slots, which from my understanding, means that we can seamlessly change from Stage -&gt; Prod, without rebuilding the project or using any pipelines. This means that the React App in both of these environments, will have the same REACT_APP_STAGE variable, but they need to be different.</p>
  <p>Does anyone have any hints or clues on how to solve this issue regarding different URLS and deployment slots?</p>
  <p>I appreciate the time!</p>