Good advice
There are many ways to store the keys. 🔑 Use the one that makes you feel comfortable.
A decent password manager is usually fine. A lot of people I know just use the notes app on their phone which seems…bad.
Many users who entered at the beginning in nostr I think they lost their keys because they are not used to saving them since there are recovery methods on other social networks. A password manager is the wisest thing that can be recommended.