Email Attachment don’t work

Hi, I’m new here bu I have the same problem.
I cannot view attachement file in email.
I put the correct tag in the File Attachment field but it’s not working.
I tried to use the option “Send Attachment as links?” and I see the link file on email but when I click the link I receive a 500 Internal Error.
This is what I see:

https://www.morettisantini.it/wp-content/uploads/wp_dndcf7_uploads/2021/01/PON_libridigitali.xls

I don’t know if the problem is in the wp-content php file (.htaccess) in which there’s:

Options -Indexes
<Files *.php>
deny from all
</Files>

Could you help me?
Thanks in advance

Bianca

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