How can i insert a value into the headshot image URL?

Hi, I am trying to create a script that displays the headshot picture of the player(that's playing and viewing). this is in a imagelabel and a local script. I wanted to change the UserId= (inside the quotations) to the players ID. How can I tell it to add a value?

script.Parent.ImageLabel.Image = "https://www.roblox.com/headshot-thumbnail/image?userId=&width=420&height=420&format=png"