Unfortunately your game isn't playable in browser. First thing is you'll want to take all the files you put in downloads after export and put them into a folder, rename the html file to index.html and zip that up and upload that. But sadly it looks like your issues go further than that, when I tried to download everything you have and run it on a localhost I get some errors, maybe a missing resource I'm not sure. Not everything is always smooth porting over to html5, I had issues that free() isn't allowed but it looks like something else might be going on for you. You can try to debug your html issues or try to upload a Windows or Mac or Linux version. A downloadable executable is a barrier for people to play, but right now no-one can get the intended experience.
That being said the music is really nice and the art and animation is cute, from what I can see.