how to link my steam to my SWTOR account

i havent played the game for 4 years and when i want to play i get an sign in option and i have no idea what my display name is of my steam game on SWTOR, i have created a new account on SWTOR site and want to link my steam to it yet it sais there is no steam account linked to this account

how can i link my steam account now to my just created account on swtor.com?