"Refund Amount" action from Shopify API

[Robles]

Hi community, 

I'm trying to implement in a custom app the option "Refund Amount" to refund a custom amount of the order. 

I was looking all the Rest API documentation but I didn't found how create the calculate refund without shipping and refund_line_items, only with a custom amount as yes is possible to do from Shopify Backoffice refund order page. 

Is possible to do it with the Shopify API? 

Thanks for all for the help. 

: ) 

[EddieLuong]

I have the same issue.  Do you figure out a way to do this? @Robles