Crazing. This zap is the zap of NWC of cashu that I bound through Freerse. It worked.

Feedback two questions,

The first zap 21sats were deducted twice 21sats. Probably because after clicking zap, I immediately went back to the cashu wallet page.

The second problem is that I zap 2sats, and the client shows success, but the cashu wallet does not deduct success.