When you install Unity, you should pick to install support for Linux or at least web. Then when you export the project, you can choose your target platform.
so it means that i have to install the unity again?
Do you use Unity Hub? It should be possible to add components like build targets with it after you have installed Unity.
I added WebGL to the project so you can play it :D
Awesome! Thank you very much! :)
:D
