how to delete record in https://njal.la/

i have one domain that in https://njal.la/,and i asked my friend to link to my website ,the domain linked to my website,now i do not want to this domain link to my website,but i can not find way to delete record in https://njal.la/,what is wrong?any one know?

Write in support, he probably is using Cloudflare... Just remove DNS or change DNS and is done.
Or your friend is doing that wrong.