Hello @AvivaP1. I see that you called into our Support team and I hope that they were able to resolve your issue.
I did want to answer your question here in case anyone else in the Community has the same question. During testing and previewing, custom fields will not appear in previewed emails as they will only show once an email is sent. In order to test to make sure that your custom fields were inserted properly, you would need to send a live email to a small group or yourself (make sure that those contacts have custom fields in their contact profiles). This way, you should see that custom information inserted into the email.
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