I find that apps that store and auto-enter passwords do not work for me. I always forget my passwords for example. And I need to write notes regarding various websites, that need more than passcodes to log in or use.
So I wrote CodeCatching. It is an app that allows you to save stuff - receipts, images of important artifacts, documents, and of course, codes. This information is shared with your other owned devices (iPhone, iPod, and iPad), through your AppleID. CodeCatching does not pretend to be secure. It only a repository - a bit better than a post-it.
But I also find that I dont need to store my passcodes/passwords exactly. I just need to have hints of that they are. For example "hat" may mean "Hatcher2008". "Holiday" may mean "!!France2019". I just need my memory jogged. This also really leaves your passwords secure.
Code Catching works for me. I hope it works for you.