Are you trying to get the path, i.e., the location of the file in the server (/home/user/public_html/wp-content/plugins…) or the url, i.e., the “web” path (https://example.com/wp-content/plugins…)?

For paths you should use plugin_dir_path, but that function doesn’t accept a dir as parameter, it accepts a file. So, depending on where are you calling it, you can try plugin_dir_path ( __FILE__ ) . 'custom/emails/attached-files/Widerrufsrecht.pdf';

If you want a URL, then you can use plugins_url, like plugins_url( 'custom/emails/attached-files/Widerrufsrecht.pdf', __FILE__ ).

If you find yourself into a directory mess, where you are too many levels deep but want to call one of those relatively to the plugins root, a good ideia is to define a constant in the main plugin file, like define( 'MY_PLUGIN_FILE', __FILE__ ); and then call plugin_dir_path ( MY_PLUGIN_FILE ) . 'custom/emails/attached-files/Widerrufsrecht.pdf' from whatever you want.

thanks for your reply. I gave it a try, but none of them was working. Because I assume the plugin folder needs to be included in the path as well I put it in front of the path, trying with slash and without slash in front.
Maybe I should explain my function a little bit more so that you are able to see what I want to achieve. I want to add an attachment to an email:

function attach_agb_pdf_to_email ( $attachments_agb , $id, $object ) {
	$agb_pdf_path = plugin_dir_path(__FILE__) . '/theme-customisation-master/custom/emails/attached-files/AGB.pdf';
	$attachments_agb[] = $agb_pdf_path;
	return $attachments_agb;
}

When storing the emails folder within my theme folder everything is working. Moving it to wp-content/plugins/theme-customisation-master/custom is the desired goal.

Thanks again for your help,

-Bj?rn

Are you using this plugin? If so, are you adding your code into custom/functions.php?

The plugin_dir_path function is just a wrapper for trailingslashit( dirname( $file ) ), so if you pass __FILE__ as paramater the function will return the directory of the current file with a trailing slash. That said, if you are calling it from theme-customisation-master/custom/functions.php, this piece of code plugin_dir_path(__FILE__) will probably return something like /home/your-folders/wordpress/wp-content/plugins/theme-customisation-master/custom/ and you just need to complete the rest. So, you can try this:

$agb_pdf_path = plugin_dir_path(__FILE__) . 'emails/attached-files/AGB.pdf';

If it doesn’t work, the best way to move foward is debugging. An echo, or a die() or some better way like xdebug will tell you what is the path returned by the function, right?

If you have any doubts just come back here!

Thank you again, that will help me a lot with my further plans. ??
Have a great day! Best regards,

-Bj?rn