In Beatflyer you can import both images and videos. The formats supported for images are PNG, JPG, GIF and videos can only be MP4.
If you are using a relatively recent version of Photoshop to design your flyers, we highly recommend to export all your layers in one click using our exporter. Fore more info on how to use it, check this tutorial.
If instead you are using Figma, you can use our plugin.
If you are using something else you can always export your layers manually from any tool. Just make sure to include the transparent areas so that the composition can be recreated without the need of repositioning the layers. If the layers are named alphabetically when dragged together in the window they will be added in order.
Generally, every time you are importing a graphic you are creating a new layer. Only exception is if you are adding an extra frame to your layer (see this tutorial).
There are many ways to add layers. You can select them clicking the pink "+" button of the left panel, or you can simply drag them from the file system to the browser or app window.