If you set up your shop to accept donations and want to send along tax receipts to customers who make donations you will need to follow the steps below.
Firstly in your shop settings a hidden attribute "Donation Product" will be created in the store, which can be found under the Attributes tab of your product details. You'll need to specify this attribute with the "Yes" value for the necessary donation products.
Then you can add your shop details to the donation receipt section. In your shop settings go into Settings section in the sidebar, then to the 'Tax Donation Receipt' section.
On this page you will input your store details. You'll need to add a minimum donation amount, list the charity or qualified donee name, address, charitable registration number, city/province, and then attach an authorized signature.
To add the authorized signature you will create your signature file on a transparent background. There are different services that help remove backgrounds on images like this one: https://www.remove.bg/
Then you will upload this transparent image to any image hosting like https://imgbb.com/
After that, you will need to copy a direct URL to this image in the png format and add it to the "Authorized Signature" field in the "Tax Donation Receipt" settings. The direct link will open the hosted image in the browser.
Once you add the link your shop settings will save the hosted image from that direct URL and add it to the receipt template in the "Authorized signature" field.
Be sure to click 'Save Changes' when you have filled in all of the Donation Receipt fields.
As a result, when customers donate over a certain amount, they will get the tax donation receipt sent to their inbox. The receipt will look like the image below as an example;