A clear translation should preserve the if-then relationship.
إِنْ تَفْتَحْ الْبَابَ أَدْخُلْ
Condition: you open the door.
Consequence: I enter.
Idiomatic translation: If you open the door, I will enter.
Urdu often uses اگر ... تو .... English normally uses if in the condition and expresses the consequence in the other clause.