With Primal, you have a some choices. You can use the built in Primal wallet for your zaps, you can setup one tap zaps with Nostr Wallet Connect if you use another wallet and that wallet supports it, or you can just use it as normal and use the wallet selectoe when the pop-up asks you to open in a wallet.

What wallet are you using with Amethyst? You can use it with Primal if you disable the Primal wallet in settings.