Customize Shopify POS receipts. About adding arbitrary items and accessing external API

[shira1]

I'm thinking of printing a receipt for the shopify POS app and have a question about customizing the receipt.

I want to get and display customer information from the server of the application developed in-house on the receipt.
We are thinking of dealing with this by customizing the receipt.
Is it possible to customize the following?
(1) Call the API of the server of the application developed in-house and acquire customer information
(2) Add the acquired information as an original item to the receipt

For customization, this page says Customize your receipt by upgrading to Shopify POS Pro.
https://help.shopify.com/en/manual/sell-in-person/shopify-pos/receipt-management/customize-receipts

It says that it can be customized, but I did not have details on what kind of customization is possible.
Therefore, I would appreciate it if you could teach me here.

I would be happy if you could get an answer.