Ident not visible

what happens if the plane caught adsb does not provide Ident ??
somebody can explain it ?

I think this may be because the aircraft signal is so weak that the aircraft’s call sign is not transmitted intact.

Two possibility.

The plane is VFR and doesn’t need to send a ident. This is under General Aviation rules.

Transponders don’t sent the ident in every message. If you missed the Ident ADSB message then you have to wait for the next one. It can take 8+ seconds to get an ident. It looks like you have received 19 messages from this plane (the messages column is the number of messages decoded from a plane). I would assume one of them would have the ident which means his transponder IDENT is set to off.