I’m trying to test the autocharge flow of the remaining payment when I’m using the preorder app but it seems to be impossible because Shopify Payment doesn’t support it in my country.
Can we use another payment gateway to checkout in this case? And whether we need to be accepted from third-party gateways to auto charge or not?
Hey Trinh!
The only alternative would be PayPal. Your customers won’t be able to purchase pre-orders via accelerated checkouts or local payment methods. (See Shopify’s help doc here.)
I recall one of our customers have a similar situation as yours. Let me reach out to him and see if he can share more info.
In the meantime, you could try chatting to Shopify Support as well.
PS. I see you’ve installed our pre-order app yesterday. Thank you! In case you haven’t seen my welcome email, just letting you know you can always reach out via the chat widget in-app to ask us any questions! We’re super friendly, promise 
Hi Jo!
Thank you so much for your help doc and the advice you gave me via email. They are really useful for me. I’ve set up Paypal to test again and hope it will run properly. I’m also using your pre-order app and it seems to be a good choice for me.
Thanks for letting me know Trinh! Fingers crossed.
We’ll be here for you when you’re ready to set up your pre-order campaigns. (Will share the suggested copy to update your Order Confirmation email + policies as well.)