Step 1: Copy the code from your Firecart dashboard


 


Step 2: Login to your Shopify Admin account Dashboard


 


Step 3: click on Setting > Checkout


 


Step 4: Scroll to “Order Processing” section & Goto “Additional content and scripts” field

 


 

Step 5: Now paste the code you copied from the Firecart account and click on the “Save” button to save the changes