The invention of the word "invention" cannot be reported to refer to a specific person.
Like many words in many languages, words themselves develop over time with a variety of factors that contribute to their evolution, such as the cultural background of a language and its interaction with other cultures, translation from one language to another, the text used to transcribe the word and its evolution;
Therefore, that "Invent" was coined to form a misnomer. I am convinced that no one invented the word "invent" and if indeed someone did, there is no way to verify the identity of this 'supposed' inventor.