Once I added Lightning Address to nostr:npub1xnf02f60r9v0e5kty33a404dm79zr7z2eepyrk5gsq3m7pwvsz2sazlpr5 , I was able to add “mints.” From now on, I can receive payments to my Lightning address offline using ecash 😅👍.

But from what I've seen in the options, there is also an option to enable ecash. Of course, this is only available in “Embedded LND Zeus”...