Postman Upload xlsx in body as binary

Hello im develop some project and need help in a Post
this post send a excel file as body
in the begin of the string they add custom string then add the binary data then another identifier string and send
for now i just receive 2 reply
internal server error
or file not attached
Im able to reproduce the upload in the firefox developer console
also have the exported curl
its very simple , maybe error in the sintaxis