Nostrize Extension users need to know your npub or nip05 in order to tip to your youtube videos.
Easiest way that I found is to put this information in youtube channel description.
Can you login to your youtube studio and navigate to "Customization" on the left menu, then select Basic Info. After that you should able to see your channel description down in the page. Edit your description to include your npub or nip05 in a new line. That's it!
After that, extension should able to read your channel's description and parse your npub. It will fetch your lightning address (lud16 field) from your nostr profile, and provide it to the user for send funds.
If you still have problems please let me know