DOM Overlay appears to be just for AR on Android Mobile devices (it doesn’t work on Meta Quest or other HMDs). There is some conversation of using WebXR Layers for rendering HTML in WebXR, but that seems to be a long ways away as it was last considered for the spec in 2022 and stagnated due to security concerns. Meta also has a new proposal that might work as long as you are okay with a modal browser window centered in your canvas.
I suggested on another thread that we might be able to pick up the Three.js implementation of HTMLMesh, which works in WebXR because it renders the canvas as a texture on a plane. Sorry to cross-post, I just realized that this thread might have been the better place for that conversation.