How can I implement a checkout button on my POS Go system?

[Bhai]

Hello, 

We just purchased a Shopify POS GO[1], and would like to implement a Button at checkout. Can you guide us on how we can access our pos go sandbox, and process to implement, this button and functions that we may require at checkout?

Thank you,

[1] https://www.shopify.com/ca/pos/meet-pos-go?utm_source=google&utm_medium=cpc&utm_campaign=RetailPOS_B...