Add to a conversation on an item using a QR code

I’m wanting to use a webform (that can accessed by scanning a QR code) to write an update on an item.

I am building an Asset Maintenance board where I want to be able to have a QR code on each asset that anyone can scan and add comment and image to an item on the board.

I can use the “write updates via email” function to enable users outside of the account to add updates, however i would like to use a simple form to submit the data rather than email.

Any ideas?