You must not take such vows as you are mandating something upon yourself which Allah didn’t mandate. Make general duaa to Allah instead.

Is it ok to take oaths like saying if i get job or my this particular problem gets solves or if my mother gets cured i will offer 10 rakahs or 4 etc. rakahs of nawafil prayers??? Or like if Allah grants me this particular wish i will offer some nawafil rakahs