QR code generator would be good. Many of the online generators don’t link directly where you ask, but through a tracking domain.

https://justaqrcode.com/

Seconded. I remember a decade ago it was really easy to find legitimate ones just by googling. Last week I literally spent 20 minutes trying to find one that didn’t use a redirect through some sketchy site. It would have taken me less time than that to install a CLI tool, vibe code it, or self-host some OSS package, but I foolishly thought it couldn’t possibly take more than 60 [additional] seconds to find one, which I kept reassuring myself again each minute of my frustrated search.

a dear friend generated a QR code for his show, used the code on flyers that he printed, made sure that the code worked, and a ~week later discovered that the qr code was now showing an ad and requesting payment to not do that

I had rarely seen him that angry - but I totally, totally got it... qr code freemium gating is such a pettily predatory business "model".