I think the safest way is to download the QR scanner by TeaCapps from the Play Store. Then go into settings to make sure it is not set to "Auto Open". That way it won't automatically open the site of the QR code you're scanning. Also, set the "Copy to Clipboard" to yes. That way it automatically copies what you're scanning to your clipboard.
Then back to the QR reader function, use the camera mode, and scan the QR code. (You will get a quick notice that it's copied to your clipboard.). Then close the app.
Next, open your browser and select "AI Mode". Then ask AI this: "Is this site safe or legitimate?" (Colon) : (And then paste the site) and enter.
AI will check it against known threat sites or phishing and give you the results.
Don't just paste the "copied to clipboard" text into your browser and search because some browsers ping the sites to make sure they exist and a few other preparations, and you don't want that. It can release your IP address, your device type, your general location, and a signal that your device is reachable.
(Note: After selecting the AI mode, the "Ask AI anything" window is normally at the bottom of the page.
If you're viewing what's at the top of the page, it's likely your last session).
Anyway, for me, the best bet is to have it checked by AI before you leap. It may come up as a "No it's not safe" and explain why, but it doesn't always mean it dangerous. It may just be a phishing attempt by a legitimate company to gain more info about you, and it's your call if you want to go ahead.