flight training

ok so i have had oxy for a little over a month now and he is now comfortable enough with his surroundings that he flies out of his room into the lounge room. at first getting him to come out of his room was a problem, i would have to pick him up off his cage to bring him out and he'd only stay with me for maybe 5min before going back to his cage. i started giving him his fave fruit only when he would sit with me.
now in the last 2days he wont stay in his room. thats mostly fine through out the day but i have a cat that comes in of an evening and occasionally refuses to go out during the day. it wouldnt be such a problem if when he flew out, he fkew to me or my partner,but he flues to the fish tank at the end of the room.
how can i control/ train him to fly to me or only on command?

i have tried to leave him in his room with the door closed when the cat is inside, but before he was flying i would have his door open with a barricade to prevent kity getting in, so now if i close the door and he knows im home he cries or if i close it too early at night.
he is a 15week old alex.
please help as i do my best to keep them separated and never leave them unattended but i have an injured back and cant move as fast as my cat.

Teach him to fly to you. Start by having him step on to your arm from his sTandy or perch and move farther and farther away so it becomes a stretch, then a jump, then a flutter, and ta da then he will be flying to you.