Hello Avira,
Thank you for your good question!
Don’t worry too much. The tag “{first name}” is just for the Test email. When you send out the campaign, it will automatically insert your customer’s first name into the text. I can see you are using the correct tag. There is no need to change it.
I was having the same worry until I found out this always happens for the Test email, even for other Email Marketing Apps like Mailchimp, Klaviyo,…
You can check out the screenshot below of the Test and Sent emails from Mailchimp. it works perfectly. (The tag looks a little different from the tag in Shopify Email as each Email Apps use their own tags system)
A small tip: Try using your email to subscribe to your own store so you can see how the email actually looks like after hitting the Sent button : )
