What was found
PDIS 731 29-02 6592 01MAR23 IND OPEN U UPON GEAR EXTENSION AT KIND GREEN HYDRAULIC QUANTITY WENT TO ZERO. ACCOMPLISHED ECAM/QRH AND LANDED ON 05L. TOWED INTO CHOCKS OFF RUNWAY. NO FURTHER ISSUES. ***EMERGENCY DECLARED*** HOSE OPENED AFT COMPARTMENT DOOR FORWARD OF APU AND FOUND GREEN HYDRAULIC RETURN LINE FAILED AFT OF THE B NUT. GREEN SYSTEM HYD LINE ELEVATOR ACTUATION IPC ITEM 120A. LEAK CHECK GOOD PERFOMED MAIN HYD POWER ADJ/TEST OPS CHECK GOOD A/C OK FOR SERVICE .