Accessing a remote database is giving an error on Laravel - php

Question

I'm trying to access a database (which exists on a different server) on my Laravel application. I keep getting the following error: SQLSTATE[HY000] [2002] Permission denied
My .env file is set up as follows (changed a bit to protect privacy):
DB_CONNECTION=mysql
DB_HOST= IP_ADDRESS
DB_PORT=3306
DB_DATABASE=DB_NAME
DB_USERNAME="laravel_user"
DB_PASSWORD="password"
I'm not sure if this is important or not but I can access the web server's database if I go to the link IP.ADDRESS/phpmyadmin
My web.php file is as follows:
Route::get('/test', function(){
return DB::select("select * from umts_list");
});
Additionally, I also went to IP_ADDRESS/phpmyadmin (where my database exists) and added a new user called laravel_user with the ability to SELECT all data and saved it with the 'password' as its password.
My attempt: I tried whatever I mentioned above and also cleared the cache since I made changes to the .env file by entering the following commands:
php artisan config: clear
php artisan cache: clear
Any help would be appreciated. Thank you.
Edit 1: On phpMyAdmin, I made sure to add the user as depicted by the following picture:
PhpMyAdmin User Account
Additionally, I also checked the port number on phpMyadmin and it is 3306 as depicted by the following image:
Port Number

Answer 1

just in case anyone else stumbles upon this post in the future, it turns out that I did not have to create an SSH tunnel or whitelist the IP. The problem was actually with SELinux. This post was the solution: Laravel permission denied on remote Mysql server (AWS aurora)
Specifically, I ran the command: sudo setsebool -P httpd_can_network_connect_db=1
This worked perfectly and it was actually blocking connection to remote databases.