There is a challenge about the possibility of publishing AR applications via WebGL. Currently, the Unity AR Foundation, ARKit, and ARCore do not support such an option, but there are another solutions.
This Unity Asset provides Image Tracking, Face Tracking, and Plane Tracking for WebGL , iOS, and Android. Moreover, you can use multiple tracking types simultaneously in a single project.
Create augmented reality experiences for the web browser using this plugin. Anchor your game objects to the floor or any surface with exceptional 6DOF tracking. Supports all major mobile browsers.
Imagine WebAR - World Tracker - WebGL - Plane Detection
Video Tutorial about Building and Testing Mobile WebGL Games and Apps made with Unity using a Local Web Server (which is hosted on your Desktop computer).
So, using a Wi-Fi network, you can connect to the Local Web Server from a Mobile Device and Test the App as fast as possible without uploading a new build every time to a Web Hosting Service.