This is a crap service. If you have any scientific writing refrain from this service. My neuroscience order was given to tourism and sociology writer. Many times asked to change the writer they said they don't have a scientific writer. The writer did not have any clue of what they are writing about. They will take your money and won't refund at all whatever you do. In the end, you will end up writing your stuff on your own after wasting lots of money and valuable time. This is the status when a completely written and peer-reviewed thesis chapter is given to frame for writing as a manuscript for publication. God help you if you are expecting something from scratch.
Please check references as the writer will blindly cite anything from anywhere and won't have any connection.