you might want to take a closer look at the retargeter options. Step 26 Motion capture data and animation retargeting never works perfect. Most Mixamo animations have the character origin shifted somewhere in the air with the IK bones left behind. To fix this go to the Animation tab and ...
It lets you export from XD to Quest and just hit Build to make it into a responisve HTML page. You select the artboards in XD you want to combine into 1 HTML page and export with the plugin. Then in Quest you can add animations, video, sound & music, CMS,...