Kindly refer to the following link(s):

Is it permissible to make Vows (Nadhr)? 

Is it permissible to fast or make an umrah to get my wish fulfilled?

Saying in sha Allah while making an oath

Is saying 'I will never do that sin again' considered to be a Vow?

Clarification: Is telling Allah I won't do this sin again, an oath that needs expiation? (promising Allah)

If I make a vow to Allah & break it several times, how many expiations must I make?

Must a person expiate every time he breaks an oath (same oath)

Expiation of breaking an oath

Made a Vow to Allah and broke it, what to do?

Made an oath but not sure if I broke it or not, must I expiate?

Oath vs. Vow & What constitutes a binding oath?

Made Promises & Oaths in past & broke them, what to do for same Oath / different Oaths

Does the reward of deed suffice for an expiation Broke oath: free slave Recite la ilaha illa..sufficient

Broke an oath, can I offer expiation for it in another country? 

How to get out of an Oath?