Deepstream-test5 detect number plate

Hi Guys

Whats the best way to get a Licence Plate from cars. I dont want to read the detail but rather save the Bounded box around the number plate. I am using deepstream-test5-aap with rtsp feed and have managed to hack my way around the plugins to save images… Please some direction would be great … I dont want to use the commercial aplr dockers as they dont fit my needs. How do I detect the number plates… should I train rather ?