Best wallet to use with Amethyst is nostr:npub1getal6ykt05fsz5nqu4uld09nfj3y3qxmv8crys4aeut53unfvlqr80nfm. http://getalby.com

It's custodial, but when you setup with their Nostr Wallet Connect service (click and hold the zap button) things go really well.