Epic deprecated support back in the 4.23 release of Unreal Engine, so developers haven't been able to export to HTML5 unlike Unity which has to this day maintained the abilit to target the browser, and in fact they are in the process of building out support for WebGPU. Check out this job ad:

https://careers.unity.com/position/software-developer-unity-...

Our startup is working on support for Unreal to support WebGPU from 4.24 onwards, and we've already upgraded support so developers can use WebGL 2.0 instead of WebGL 1.0 like was available previously before Epic made it a community supported platform extension.