NEED TO GAIN WEIGHT

Anybody have tips for gaining weight? I’ve used other sites but haven’t came across one that was beneficial for me. Ive spoken to people about it but all they keep saying is “you’re beautiful the way you are! why would you ever want to gain weight?” i know i’m underweight and i just want a few extra lbs(10-15) to be in the healthy weight range😊

and when i do gain weight it’s always in my tummy, id like to gain in the RIGHT regions if you know what i mean😂