I need to create a draft order with a subscription line item. So, I was going to the documentation https://shopify.dev/api/admin/graphql/reference/orders/draftorder , I noticed the custom attributes which further lead me to https://shopify.dev/api/admin/graphql/reference/orders/attribute , indicating SubscriptionLine.customAttributes .
So please can anyone will this parameter helps to crack my initial requirement "creating a draft order with a subscription line item" or what exactly the custom attribute or SubscriptionLine.customAttributes is?
Unfortunately, subscriptions aren't yet supported for draft orders: https://shopify.dev/apps/subscriptions#known-limitations.
Custom attributes in our API are fields that are for the use of your application. Shopify only stores and forwards the custom attributes.
If I haven't answered your question, please let me know, and I'll be happy to give it another try.