In a Tweet yesterday afternoon Google announced a neat little addition to Google Expeditions. You can now share a link to a specific scene within an Expedition.
Previously if you wanted to get all of your students onto the same scene at the same time you had to guide them through the whole Expedition. Now you can just give them a link (posting it in Google Classroom would be a convenient option) and they can click it to jump to the scene. And just like any other URL, you could share it via QR code. My tool of choice for making QR codes is QR Droid, but any QR code generator should work for you.
If you’re looking for some help getting started with Google Expeditions, I have a collection of tutorial videos here.
— Google for Education (@GoogleForEdu) September 12, 2019