Should a woman confess to her husband that she does not wear the hijab and he refuses divorce, or should she continue to conceal it from him, given that she does not wish to wear it and does not see it as compulsion in religion, bearing in mind that she is not immodestly dressed and wears makeup with the hijab?

The husband's statement, "If you don't wear it [the hijab], I will divorce you," does not constitute a divorce, as it is merely a threat. Hijab is an obligatory duty for the Muslim woman, and the meaning of "there is no compulsion in religion" pertains to entering the religion, not to adhering to its rulings. Therefore, the wife must obey her Lord and respond to His commands. There is no harm in not informing her husband of her shortcoming until she commits to wearing the hijab. The obligatory hijab refers to covering the entire body except for the face and hands, and covering the face is more cautious.