From Longman Dictionary of Contemporary Englishearn/win your spursearn/win your spursto show that you deserve to succeed because you have the right skills → spur
Examples from the Corpus
earn/win your spurs• Now he has won his spurs, he can afford to recognise mistakes like that without fearing loss of face.• But thanks to Sheila, now you don't have to go all the way to Dodge City to win your spurs.• David had done absolutely nothing to earn his spurs when Samuel anointed him.• Pistoliers are young nobles who have yet to win their spurs and assume their rightful position as Knights of the Empire. 