How do I manage constantly changing security codes when using Apple Cash online?

I use Apple cash online. It's most often (always) very difficult because the security code changes.My screen becomes full of various apps and I am simply attempting to reload my Amazon Card - or purchases on other sites. I usually take a screenshot. That is even worse. It clutters my screen and confuses me because the security code changes. Will someone please offer a suggestion to me? ManyThanks.

[Re-Titled by Moderator]