How do I scan a QR code with Galaxy a12?

I'm another who has an A12 with NO built-in QR scanner.  There aren't any switches mentioning QR in my camera or indeed  anywhere on my phone... except that after an afternoon with Samsung tech help I ended up turning on a QR capability under developer options that was supposed to  fill in for what I'm missing but actually only wants to do what it says: "Pair device with QR code". Frustration continues. The many free apps are full of 'accidental on purpose' clicks. Hate 'em