I am unable to run adb shell screenrecord /sdcard/my.mp4
Device specification that i am trying to run this command:
You need to undestand whe does adb shell screenrecord /sdcard/my.mp4
mean. It means execution "screenrecord" command in your phone's shell. You could do the same by installing any terminal emulator on your phone, run it and type (on phone) screenrecord /sdcard/my.mp4
You are getting "command not found" error, it means there is no "screenrecord" command available. Most devices should have it included, but it seems your device have it missing.