Problem in Encryption library

Hi
I use encryption library in Codeigniter
There is a big problem
I try use below code for encrypt data

PHP Code:

$this->load->library('encryption');
        $this->encryption->initialize(
        array('driver' => 'openssl',
                'cipher' => 'aes-128',
                'mode' => 'ecb',
                'key' => '1111111111111111'
        ));
        
        echo $this->encryption->encrypt('omid'); 


And try decrypt in https://www.devglan.com/online-tools/aes...decryption
But this site cannot decrypt it
Why?
I need encrypt data and can decrypt in any programming language easily