My project got a very large .pck file and it takes a LOT of time to load on a website, does anyone know how I can solve this problem?
What problem? That it takes a long time to download a large file? Remove unused files from your project and keep your media files as small as possible - that's the easiest you can do and usually enough. If your project and website allow for it, you can also split your game into multiple smaller resource packs and load them in the background.
I tried to split my game into several smaller resource packs and load them in the background, but how do I load them? I only know how to upload local files. When I export and post it on a website, I don't know how to load it in the background.