How to redeem it using Minibits app if I’m the npub owner?
Discussion
It would work with Minibits out of the box if it's been locked to wallet pubkey.
You can import arbitrary nostr keypair to minibits, but it breaks lightning address functionality, so I'd say it's not worth the effort.
For Nicolas the proper way is to write a script, e.g. leveraging cashu-ts lib.