Convert XLTX to ACCDE

xltx to accde conversion would be something like export or use of MS Excel template to MS Access database, something that does not much much sense. At best you can export/import data from MS Excel spreadsheets and save them as regular Access databases, but for templates this does not make much sense. You have to actually look for the .xlsx file and not the template.

Simply put, it is impossible to convert XLTX to ACCDE directly.
Thus, there is no so-called xltx to accde converter or a free online xltx to accde converter to be found.