For Shopify Valu integration only you will need to do the steps below.

-Create a private app, please follow the guide here,    

-Then you will need to create a private app on your website with a "read and write access permission to: Orders, transactions, and fulfillments". 

Please send us the following information at
-API key
-Password for the private app
-Your store URL
-Storefront access token
-Valu Iframe ID (contact us to create one from our side)