Setting a lightning address on your profile is for receiving zaps and not for sending zaps. Looks like you have an NWC misconfigured with Amethyst. Maybe nostr:npub18ams6ewn5aj2n3wt2qawzglx9mr4nzksxhvrdc4gzrecw7n5tvjqctp424 can help you with that. I don’t use Amethyst much and couldn’t figure out where to access NWC settings. WoS does not support NWC so you probably have to reset your NWC settings so that you can have Amethyst prompt you to ask which wallet you want to zap with. When I click zap in Amethyst, it prompts me to ask which wallet I want to use.