With the launch of Creative Cloud express, we have changed how Adobe Stock works within the app. If you are a free user, you have access to hundreds of thousands of images that are available without cost. Adding them to your project will cause them to show up in your license history, but you are not using credits to license them.
If you are a paid Creative Cloud Express user, you can also use any of the photos that have a crown in the corner. This gives you access to over 160 Million photos from Adobe Stock. You can use these in your Creative Cloud Express projects as part of your subscription, but they are not available outside the app.
If you are a paid stock user, you can still license images on stock.adobe.com and those images will be available in Creative Cloud Express regardless of whether you are a free or paid user.