Can someone help me with importing animations into a game engine?
What problems are you running into specifically? With a question that generic, it’s hard to offer any helpful input.
Is there a particular import format you need? Most engines support importing spritesheets, which Aseprite can export via File > Export Sprite Sheet. Some engines also accept GIFs, which you can create via File > Export.... If you export as a spritesheet and don’t trim the individual cels, you should have no trouble importing the spritesheets, all you need to know is how big your canvas is (plus any padding you decide to add), the frame durations, and if you have multiple animations in one document, which frames make up which animation (something you can generally recreate in-engine).
If you want to be able to trim your animations to save space or want to automatically use Aseprite’s frame durations and tags, then you’ll want to use the spritesheet export option to also output a JSON file, which describes where on the spritesheet each frame is and how exactly it’s used. I’m not aware of any engines that support this JSON data out of the box, but it’s pretty easy to parse and the various fields are largely self-explanatory, so take a look at the output JSON in a text editor and you’ll figure it out soon enough.
The hardest part is probably the descriptions of trimmed frames:
frame describes the bounding box of the frame on the spritesheet. This includes the padding.
sourceSize is the size of the frame prior to trimming, it’ll generally be the same for all the frames in a single export, your canvas size.
spriteSourceSize describes where on the canvas the frame was and how big it was. You will use this data to offset the drawing of the sprite when rendering each frame so that the frames are all aligned. This does not include the padding, so if your sprites are padded, you’ll want to account for that when positioning them.