Programs enabling conversion of the file:
If your objective is to convert the file from DOTX to the file DOTM, you can use any of the applications listed. DOTX to DOTM conversion process in every program intended for this purpose (so-called converters) is very intuitive and everyone is able to manage converting a file.
However, bear in mind that the list may also include programs to support and work with the indicated extensions DOTX and DOTM - and not only converters. In such a case, you need to open the source file DOTX and from the options available in the program, choose ”Save as... DOTM" or "Export to DOTM".