Sitelinks Search box schema confusion

Without getting into the structured data itself, it is important to remember that the actual url on which wordpress will run the search has to be the home page. If you are using “pretty permalinks” wordpress will probably try to parse the url as content, not as search for almost anything that is not the home page. So you target URL should probably be example.com/?s= .

The other thing that looks fishy is the use of “{}”. If google sends it and not just use it for parameter formatting, than you should not use it as it will most likely break the wordpress search (or more accurate, you will not get results).

As for the structure itself, it seems like the name you use for the parameter is not important by itself, as long as you use the same string the two attributes in which it is being specified and used.