What is the ruling on a wife separating from her husband, whom she married by an 'urfi (customary) contract, and her desire for a Shar'i (Islamic legal) divorce from him after he began financially blackmailing her and refusing to divorce her?

If the husband withholds his wife's due rights according to Sharia, such as maintenance, and orders her to commit something forbidden, like being alone with a stranger to obtain money, then she is permitted to seek divorce (talaq) or annulment (khul'). If the wife cannot resolve the issue herself, she should resort to the Sharia courts. In the absence of formal marriage documents, the wife can consult a lawyer to understand the laws that oblige the husband to divorce or annul the marriage. If all these attempts fail, there is no option but to reconcile with the husband and involve influential people to persuade him to accept the divorce or annulment.