GraphQL APIs for Order checkout

[Vinita_Kasliwal]

Dear Experts

I am developing an app and using GraphQL apis 

When the user checkout what all API should be used

I am not able to get the order ID 

I checked this one 

https://shopify.dev/tutorials/create-a-checkout-with-storefront-api

As well as this link 

https://shopify.dev/docs/admin-api/graphql/reference

Both do not have the order ID being returned as a response 

Can you please confirm how I get that

After I Get the order Id from the checkout process is when I should be calling the payment gateway service right?

Kindly help understand the end to end flow. 

Regards

Vinita

[Vinita_Kasliwal]

Is there anyone who could answer and assist?