Kidney stone 6mm hydeoureteronephrosis.

Hello Doctor, I have attached the ultrasound report. It shows a 6 mm stone in the lower left ureter, close to the VUJ, with moderate hydroureteronephrosis. He sometimes has very severe pain, followed by vomiting, and at times he vomits even after eating anything. He also sometimes has difficulty passing urine. Could you please advise: Does this level of blockage require urgent treatment? Should we do RFT/KFT, urine routine/CUE, urine culture and CBC now? Can we wait for the 6 mm stone to pass naturally, or would you recommend laser/ureteroscopy? If medicines are appropriate to help the stone pass, what should he take and for how long? Does the moderate hydroureteronephrosis need any immediate treatment or monitoring? Please advise what the next step should be. I'm attaching reports