Can both male and female have their nikkah without their parents knowing but later informing everyone and have a wedding?

As-salamu alaykum, I am curious to know whether the marriage would be valid if the couple were to go off and have their nikkah with an imaam without any approval from parents on both sides. Back story: I (female) am not ready to tell my parents about getting married as the person I want to get married too is not stable enough and has only just graduated from university however I do know my parents will give their approval He knows his parents will not accept the marriage as it will be an interracial marriage therefore wants to make sure he is financially stable and has his own place before telling his parents as he knows they will kick him out. If we was to get have a nikkah without telling both our families would it be valid and then later on telling our parents and having a wedding to make it “official” to everyone else