Is the prayer of a woman who is adorned, unveiled, and not wearing hijab invalid if she prays in the street in the presence of non-mahram men because the time for prayer has arrived?

A woman's prayer with an uncovered head is not valid, whether she is at home or outside. However, if the prayer time is becoming short and she cannot find the lawful attire, she should pray in her current state due to the sanctity of the time, and then repeat the prayer while properly covered.