Advanced Custom Forms PHP formatting for do_shortcode

Even though you are echoing the shortcode, I think you still need to echo the ACF field inside the string of the do_shortcode function.
Change your ACF field return function for the_field() :

<?php echo do_shortcode("[tnc-pdf-viewer-iframe file=".the_field('document_link')." width="900px" height="700px" download="false" print="false" fullscreen="true" share="true" zoom="true" open="true" pagenav="true" logo="true" find="true" current_view="true" rotate="true" handtool="true" doc_prop="true" toggle_menu="true" toggle_left="true" scroll="true" spread="true" language="en-US" page="" default_zoom="" pagemode=“”]");?php>

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)