How to grow hair super super long?

My hair isnt long at all and I want super long hair... its also really flat and i want it to be volumous and shiny. I bought biotin gummies to start talking but i started birth control so i stopped taking them and idk if they would have even worked. any tips or anything to grow my hair out? this is how long it is right now and i want it atleast down to the middle of my back.