Hi , if you have lost your sim-card then u need to contact “3 “ store or support on telephone to get a new one .

It goes faster if you go to a local 3 store and they will help you quickly . And you need ID ,driver license or something thats tells it is you . 

Best regards F 

@Amir Algomaa 

@Amir Algomaa Hello,

as @frodrik91 says, you will need a new sim-card which you can obtain by contacting Three customer service or by visiting a Three-store. You can also order one through “Mitt3” - and if your phone supports eSIM you will get a QR-code presented directly which you can use to activate the eSIM in your phone right away.