Debug data about Ninja Forms File Uploads, install as a normal plugin or as an mu-plugin.

ninja-forms-uploads-debugger.php

<?php
/**
 * Plugin Name: Ninja Forms Uploads Debugger
 * Plugin URI: https://ninjaforms.com/extensions/file-uploads/
 * Description: Debugger plugin
 * Version: 3.0
 * Author: polevaultweb
 * Author URI: https://polevaultweb.com
 */

function nf_fu_debugger() {
	if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
		return;
	}

	if ( ! isset( $_GET['page'] ) || 'ninja-forms-uploads' !== $_GET['page'] ) {
		return;
	}

	if ( ! isset( $_GET['tab'] ) || 'debug' !== $_GET['tab'] ) {
		return;
	}

	$html = '<div id="nf-upload-debugger">';

	$html .= '<strong>NF_File_Uploads()->controllers->uploads->get_path():</strong>';
	$html .= '<br>';
	$html .= NF_File_Uploads()->controllers->uploads->get_path();
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>wp_upload_dir()["basedir"]</strong>';
	$html .= '<br>';
	$uploads = wp_upload_dir();
	$html .= $uploads['basedir'];
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>WP_CONTENT_DIR</strong>';
	$html .= '<br>';
	$html .= WP_CONTENT_DIR;
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>ABSPATH</strong>';
	$html .= '<br>';
	$html .= ABSPATH;
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>NF_File_Uploads()->controllers->settings->get_max_file_size_mb()</strong>';
	$html .= '<br>';
	$html .= NF_File_Uploads()->controllers->settings->get_max_file_size_mb();
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>ini_get( \'upload_max_filesize\' )</strong>';
	$html .= '<br>';
	$html .= ini_get( 'upload_max_filesize' );
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>NF_File_Uploads()->controllers->settings->get_setting( \'max_filesize\' )</strong>';
	$html .= '<br>';
	$html .=  NF_File_Uploads()->controllers->settings->get_setting( 'max_filesize' );
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>NF_File_Uploads()->controllers->settings->max_filesize()</strong>';
	$html .= '<br>';
	$html .=  NF_File_Uploads()->controllers->settings->max_filesize();
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>NF_FU_Helper::max_upload_mb_int();</strong>';
	$html .= '<br>';
	$html .=  NF_FU_Helper::max_upload_mb_int();
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>ini_get( \'post_max_size\' )</strong>';
	$html .= '<br>';
	$html .= ini_get( 'post_max_size' );
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>ini_get( \'max_execution_time\' )</strong>';
	$html .= '<br>';
	$html .= ini_get( 'max_execution_time' );
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>ini_get( \'max_input_time\' )</strong>';
	$html .= '<br>';
	$html .= ini_get( 'max_input_time' );
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>ini_get( \'memory_limit\' )</strong>';
	$html .= '<br>';
	$html .= ini_get( 'memory_limit' );
	$html .= '<br>';
	$html .= '<br>';

	$html .= '<strong>php.ini location</strong>';
	$html .= '<br>';
	$html .= php_ini_loaded_file();
	$html .= '<br>';
	$html .= '<br>';



	$html .= '</div>';

	print $html;
?>
	<script>
	 jQuery( document ).ready( function( $ ) {
		 jQuery("#nf-upload-debugger").appendTo("#poststuff");
	 } );
	</script>
<?php

}

add_filter( 'ninja_forms_uploads_tabs', 'nf_fu_debugger_load' );
function nf_fu_debugger_load( $tabs ) {
	$tabs['debug'] = __( 'Debugger', 'ninja-forms-uploads' );

	nf_fu_debugger();

	return $tabs;
}