Does potassium chloride contain oxygen

NO!!!!

Potassium chloride has the formula 'KCl' . This is one atom/ion of potassium and one atom/ion of chlorine. There is NO oxygen present, so you cannot produce oxygen.

However, potassium chlorate has the formula 'KClO3' . This is one atom of potassium , one atom of chlorine and three atoms of oxygen. So potassium chlorate will decompose to produce oxygen.

NB Note the spellings and the formulae of both substances.