If you enter your NWC string on some website, consider using a seperate lnbits subwallet instead of exposing all your funds. Your nwc string authorizes whoever has it to access all the lightning funds on your node.
(You can set budgets which mitigates this a little, it's still saver to expose only whatever you are willing to risk. Also clients who use the string only locally aren't as much at risk as online databases)