For File attachments plugin, you can use the
Compiler and compile the package already coming up with this add-on in.
There may be some difficulties with this add-on if you upload from Google Chrome. Chrome appears to be not secured enough to handle .zip files, which are considered as "application/octet-stream",
not "application/zip".
If you are in doubt, you can skip losing lots of time and refer to our paid support.
Installation of the add-on could be in just $6 dollars range, but then you will be sure it's working and configured properly.