Add Download Invoice button to Shopify's confirmation email
This guideline gives information about how to add Download button to the Shopify's confirmation email which is sent to your customer.
Step 1:
In our app, select Settings => Frontend Download option on the sidebar:

Then:
Select option for Order or Draft order
(In this article, it is about Order. To access setup for Draft order, please go to this LINK
Edit everything as you wish
Preview the buttons
Scroll down and click Copy to copy the code

Step 2:
In your Shopify admin page, go to Settings -> Notifications -> Order confirmation:

Paste the code from Step 1 onto Email Body (HTML), normally right before </body> tag at the bottom:
Click Save to finish.
Then you can make a test order on Shopify to see what it really looks like.
Step 1:
In our app, select Settings => Frontend Download option on the sidebar:

Then:
Select option for Order or Draft order
(In this article, it is about Order. To access setup for Draft order, please go to this LINK
Edit everything as you wish
Preview the buttons
Scroll down and click Copy to copy the code

Step 2:
In your Shopify admin page, go to Settings -> Notifications -> Order confirmation:

Paste the code from Step 1 onto Email Body (HTML), normally right before </body> tag at the bottom:
Click Save to finish.
Then you can make a test order on Shopify to see what it really looks like.
Updated on: 21/04/2023
Thank you!