Thanks for providing your domain!
Taking a look at your store, I’m not quite sure how to add a product to my cart. I was able to select a product where I could choose a pattern, which redirected me to an external site: maggy55patterns.com. When at the checkout for this store I am able to see American Express as a payment option.
Is maggy55patterns.com also a store you own? If so, have you checked the payment settings for that account?
In the meantime, for bagmakersworkshop.com I recommend you add a logo! You can actually create beautiful free logos over at canva.com.