I’ve seen dedicated hardware devices which scan a QR-like code and show this in a little screen of their own. The bank provides them and does not require any app.
I only know of a single bank using this.
I only know of a single bank using this.
If it's not Crédit Mutuel then you now know of a second bank using this method.
Meanwhile, the last hope is that people will use more cash (if the digital world is too hostile, oh wait it is!)