Yes you can bring your own nsec ... on https://rizful.com/get_on_nostr_today .... you can see "(If already have a private key, that's fine too. You can bring your own private key and still use Rizful.)"
It really shouldn't require an "experienced user". I'd say it requires enough technical sophistication to look at this page and not be terrified: https://rizful.com/get_on_nostr_today
Yes you can bring your own nsec ... on https://rizful.com/get_on_nostr_today .... you can see "(If already have a private key, that's fine too. You can bring your own private key and still use Rizful.)"