What is the ruling regarding the waiting period (iddah) for a woman whose husband divorced her twice and then went missing? Is it permissible to propose to her after the divorce proceedings are concluded?

If a man divorces his wife and does not take her back, and then he goes missing, her waiting period (iddah) begins from the time of the divorce. It ends after three menstrual cycles for a menstruating woman, or upon giving birth for a pregnant woman, or after three months for a non-menstruating woman. Once her waiting period ends, it is permissible for her to marry another man.