It appears I am not the only one with this problem as a Google search reveals others in my same spot:
However it has been a week since I downloaded AnkiMobile and it is still not showing up in my iOS Settings page. I’m on the latest version of iOS 13. I’ve tried restarting my phone, deleting and re-downloading Anki, deleting other apps, logging in and out, but nothing works. When I download brand new iOS apps or when I delete & re-install existing iOS apps they all show up in the Settings page immediately; this problem seems localized to Anki…
Any help or suggestions?