Developer mode for usb dubbing

[Kumarbadal1234]

Dear sir, how can I enable developer mode in galaxy A51 . I tried many method like - go to in settings, click on "About phone" after that click on software information, tap 7 times on build number but sir the developer mode did not open or show . 

[Sidhabhi]

If you have purchased your device through Samsung finance+,then wait till emi gets completed,after that developer options will come

[HaddGareeb]

Does it lead to void warranty?