Hi !
You only export your Unity Scene, so people that don't have unity on their PC won't be able to play your game.
Plus, only exporting your scene makes your project unplayable because it miss all you scripts, materials, etc.
I don't know if you already know that but just in case...
To export your game :
Go to File > Build Settings
Select the platform you want to export your game for (WebGL on my screen)
Be sure to include the scene you use in the "Scene in Build view" by drag and dropping them.
Then press Build!
(More information here : https://docs.unity3d.com/Manual/PublishingBuilds.html)
Hope I can try your game soon!