the file names will not show in the email.
Since you are using file upload to upload the files to the server, you will need to use the entered value option on the attachments tab.
click the lightning bolt next to entered value and then expand the WA Uploaded Files (file_01) binding group. Select the server directory binding, this will add the following code:
<?php echo $WA_DFP_UploadStatus["WA_UploadResult1"]["serverDirectory"]; ?>
copy that, then click the lightning bolt again, this time, select the server file name variable. the code will now look like this:
<?php echo $WA_DFP_UploadStatus["WA_UploadResult1"]["serverFileName"]; ?>
Past the server directory code in front of that so the entire code is:
<?php echo $WA_DFP_UploadStatus["WA_UploadResult1"]["serverDirectory"]; ?><?php echo $WA_DFP_UploadStatus["WA_UploadResult1"]["serverFileName"]; ?>
add another entered fvalue for the atachements and use the same steps, except get the variables from the WA Uploaded Files (file_01) binding group, the final code will look like:
<?php echo $WA_DFP_UploadStatus["WA_UploadResult2"]["serverDirectory"]; ?><?php echo $WA_DFP_UploadStatus["WA_UploadResult2"]["serverFileName"]; ?>
To restrict a file type by extension, use the File Extension validation type, not the restrict content type.