The @ Shortkeys dropdown (on Compose, Templates and Sequences) inserts one of these placeholders at the cursor:

• Company Name, Company Phone, Company Email, Company Address, Company Website – from your business settings.
• Customer Name (first + last), Customer Phone, Customer Email, Customer Address (shipping address, town, state, zip and shipping phone), Customer Birthday.
• Cart URL – the link to your site's cart page.

Placeholders look like `{{customer_name}}` in the editor and are replaced individually for each recipient at the moment the message is sent. Contacts that are not customers (imported numbers) have no customer data, so customer fields come out blank for them.