Designing and building a webpage can be complicated. Structured data is when data is organized in a format in the database, specifically Google's massive one, that makes it easier to process and analyze. This leads to a question that is frequently raised; is it possible to insert structured data at the bottom of the <body> tag instead of at the <head>?
JSON-ld is structured data that Google uses to read a webpage. Other data that can be similarly utilized is RDFa and Microdata.
So, the answer to the question is yes; the JSON-ld structured data can be placed in either the head or the body of a web page.