1.  Automations fulfillment.

Step 1: Go to Automations.

Step 2: Choose the name of the automation that you want to send receipts when fulfilling orders.

Step 3: Allow send fulfillment receipt.

In the Customers, tick on the Allow send fulfillment receipt.

Step 4: Save.

2. Manual fulfillment.

Step 1: Click Upload Fulfilments.

Go to the Fulfillments section, then click Upload Fulfillments.

Step 2: Choose the Basic template.

Step 3: Set up fulfillment.

In this step, you need to upload a file, choose a location, and tick on Allow send fulfillment receipt.

Then click Start fulfillment.