It appears you want to send HTML in the HTTP module’s body?
In that case you should use a Text Aggregator instead of an Array aggregator.
Example Output
Hope this helps! Let me know if there are any further questions or issues.
— @samliew
P.S.: Did you know, the concepts of about 70% of questions asked on this forum are already covered in the Make Academy. Investing some effort into it will save you lots of time and frustration using Make later!