Contact Form 7 to External DB 2018

cf7_external_db2018.php

<?php
/*
Plugin Name: Contact Form 7 to External DB
Plugin URI: 
Description: This plugin uses the wpcf7_before_send_mail hook to post a specific form to an external database. Upon use the details for your external database will need to be entered. Private use only.
Author: 
Version: 0.2
Author URI: 
*/

function wpcf7_send_to_external ( $cf7 ) {

	//external db details
	$username = 'username';
	$password = 'password';
	$database = 'database';
	$host = 'host_ip';

	//create new wpdb instance
	$mydb = new wpdb($username, $password, $database, $host);
    
    	//limit hook to only fire on particular form ID (optional)
	    if ( $cf7->id == 1 ) {

		//get select box for different enquiry types (optional)
		$type = $cf7->posted_data["your-select"];

		//if form type is equal to above value (optional)
		if ( $type == 'Form Name' ){

			//code added for wordpress 4.9 2018
			$cf7 = WPCF7_ContactForm::get_current();
    			$submission = WPCF7_Submission::get_instance();
			$data = $submission->get_posted_data();
			
			
			//get posted form fields
			//these are example form fields
			$field1 = $data["name"];
			$field2 = $data["email"];
			$field3 = $data["address"];
			$field4 = $data["city"];
			$field5 = $data["state"];
			$field6 = $data["zip"];
			$field7 = $data["phone"];
			
			
			//insert into external db
			$mydb->insert( 
				//name of external db table
				'table_name',
				//name of table columns and which fields to insert 
				//these are example fields
				array( 
					'name' => $field1, 
					'email' => $field2,
					'address' => $field3,
					'city' => $field4,
					'state' => $field5,
					'zip' => $field6,
					'phone' => $field7	

				),
				//field formats: %s = string, %d = integer, %f = float
				array( 
					'%s','%s','%s','%s','%s','%s','%s'
				) 
			);

		}

	}

}
add_action("wpcf7_before_send_mail", "wpcf7_send_to_external");

I put this code in the contact-form-functions.php first and that crashed the entire website - could no longer log into wordpress. Placed in functions.php (within the contact form 7 - includes plugin directory) and it crashed the system as well. Can anyone tell me where to place this code so it does not crash the system?

Automatically generate table and columns and save to external DB https://wpdebuglog.com/forums/topic/contact-form-7-external-database-mysql-easy-method/