From your Shopify admin, click on Apps and select Restockify
Click on Import in the Request section
Download the sample CSV template.
The sample CSV file includes three fields: Email, Product URL, and Date.
You can just open your own file and make the changes, so your own file looks like the sample file.
Here are the columns you need to have in your CSV file:
The email address of your subscriber (e.g., firstname.lastname@example.org)
The product URL that the subscriber has requested (e.g., https://sample.myshopify.com/products/awsome-shoe?variant=37969409802410)
Phone number of your subscriber. ( remember, it needs the + at the beginning of it.
The date that the subscriber has requested. (e.g., 2021-04-13)
6. After setting up your CSV file, click Add file.
7. Select your file and upload it to the dashboard.
Now, you'll get a confirmation email saying your import request is in process. This email is sent to the email set in Setting> General. After a few minutes, based on the size of your file, you will receive the second email. In this email, you can see how many rows have been imported and download a file in which you can see any errors in your records. You can then fix them and import them again.