It depends:
When you drew a circle using App Inventor Classic (or was this using ASP), you were probably drawing on a Google Static Map. If you will on a Google Static Map, try the advice here https://stackoverflow.com/questions/36506668/google-static-map-draw-a-circle and provide appropriate App Inventor Blocks.
If you are drawing on an OpenStreetMap tile use Circle along with the Map component. This is the simple way to draw a circle using the MIT Map component. You could use Blocks like these
