The _ parameter isn’t actually required - it is just there as a “cache buster”. You can remove it.
Also, you are looking at the incorrect request in your developer tools. You should be looking at the request that happens when you click the “save” button. (You will need to tick “preserve log” in dev tools so that the request doesn’t dissappear when the page reloads). Look for a PUT request to /categories/192.
Another thing to watch out for is that your parameters need to be urlencoded. In postman, you do this by changing from “form-data” to “x-www-form-urlencoded”.
Hope that helps get you a little bit closer!