Can I marry my ex wife? She took khula from me but i can’t take her out of my heart and I would like to propose again. She is still single. I heard someone saying that she has to marry another man, have intercourse with him divorce him wait for iddah and then she can marry me

She would need to agree because the conditions of khul’a are that the wife has aversion and she gives a badhl. Moreover, a new marriage contract would need to be enacted. Thus, if you would like to remarry her then you have to determine her willingness.

A new marriage contract would need to be enacted for you and her. For what you heard, it is for a different situation, someone who has divorced his wife and returned/remarried her twice, then upon the third divorce there is a requirement of her marrying another man (and intercourse), getting divorced from him, and then she can marry the first husband again.