Eed21

I am living abroad and recently started to rent out a property in the UK. I am in the process of sending a paper copy to register for self assessment (I tried multiple times online and it seems that I cannot from abroad) and the estate agent takes the taxes to hmrc already. Is there a reason for me to fill out the nrl1 to send the tax to hmrc myself? Is there another way I need to inform hmrc other than the self assessment?