You texted knight story about King? It’s not the same (6)
I believe the answer is:
unlike
'not the same' is the definition.
I can't judge whether this defines the answer.
'you texted knight story about king?' is the wordplay.
'you texted' becomes 'U' (text abbreviation for 'you').
'knight' becomes 'N' (chess abbreviation).
'story' becomes 'lie' (story can mean a fabrication).
'about' means one lot of letters goes inside another.
'king?' becomes 'K' (chess abbreviation).
'lie' going around 'k' is 'like'.
'u'+'n'+'like'='UNLIKE'
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for unlike that I've seen before include "Not similar or comparable to" , "Dissimilar" , "Different from" .)