How to send email with personalised purchased products

I am new to Klaviyo and my situation is that: My shop work in POD sector, and almost customer buy 1 time and dont return. I send email to collect their feedback but I’m finding how to make them know who am I and what my company is. Thus, I want to remind the their recently purchased product in the email but I cant find where to put this information.

For example: MrA purchased item B from my store. My email will be: We are the store that provided item B to you.

Question: How to set item B automatically in the email like: {{ first_name|default:'there' }}