To use that site you do need to login with your nostr key. 

Generally, it's safer to user a signing extension though, instead of pasting you nsec in to random sites. 

You can read about which extensions to use here: https://orangepill.dev/nostr-guides/guide-nostr-key-generation-and-management/#nos2x-nos2x-fox-and-alby-nostr-signer-extensions  

 Thanks, 💜 I did it with nos2x. It was my first time. I think I was too lazy before. 😅 

 Get Alby! 

 I have. I use it for other accounts 

 Though it is not as easy cuase it wants a passcode. I have to go to another extention to get its passcode or open my notebook