What is the ruling of Islamic law regarding divorcing a wife whom I was forced to marry, and after the marriage, I discovered that she is pregnant and not a virgin from another man?

For a marriage to be valid, the conditions of the guardian (wali) and witnesses must be met. If the marriage takes place without the guardian's permission, it is void (batil) and must be annulled or dissolved. If consummation occurs in such a void marriage, its effects follow: the wife is entitled to the named dower (mahr musamma), and the child is attributed to the husband if born after six months from the contract date. However, if the marriage is concluded with the guardian's consent, it is valid, and the husband has the choice to either retain his wife or divorce her. It is worth noting that if a guardian refuses to marry off his ward without a valid শরঈ (Shar'i) justification, she is allowed to refer the matter to a judge. Moreover, marriage under moral pressure is not considered coercion.