@esy_cari2020, FYR, you could follow this post discussed previously:
@esy_cari2020, I could also see some age group being overlapped like (21, 35). Maybe you will also need to fix the criteria.
Your formula used for calculating age also seems OK. But we too have other workarounds to calculate age if you wish to try out.
Sorry, I did not get the last one regarding the QR code. BTW, it’s always good to have a separate topic if you have separate issues. This should help the community with the search index.