Typically this error appears because the store does not have an available payment processor enabled. Could you head to Settings/Payment Providers and let me know if you have a payment processor setup? If yes, could you share a screenshot of what you're seeing? If no, then you'll want to select a payment processor from the list of available payment options and follow the prompts to get one setup. Once done, you should then be able to accept payments in your store.
You are currently using Stripe as your credit card payment processor and not Shopify Payments. A store can only have one credit card processor enabled at a time which is why you are not seeing Shopify Payments appearing. A credit card option should still be appearing at checkout; however, the payments will be processed directly through Stripe and not Shopify Payments.