OSD programming tool
Make sure the DTR is connected to GRN of MINI OSD.
Update your mini OSD, please download the software ArduCam from here,
https://download.ardupilot.org/downloads/wiki/advanced_user_tools/Config_OSD_20.zip
more information ,you can read here,https://diydrones.com/profiles/blogs/arducam-osd-v2-0-update-your-minimosd