The most common and most likely answer to this crossword clue is the 13 letter word DO ONE’S DUTY
I've seen this crossword clue in The Guardian
D
O
Â
O
N
E
â
€
™
S
Â
D
U
T
Y
Buddy explains!
The straight part
We know that "Obey" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case obey = do one’s duty.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.