"Juh now (or just now)" means to tell someone to wait for a while. Same expression as "in a minute, wait (a minute)!, hold on (a minute)!, hol' up (deh)!, etc
1) Johnson, can you get me a glass of water please?
2) Juh now, juh now, I busy on the call wid someone (Wait, wait, I am busy. I'm on the phone (with someone))
1) Oye, call mate deh for me!
2) Just now! (Wait for a while!)