If the theme doesn't have an interface for adding scripts to header or footer, you would have to either edit theme files (bad,) set up a child theme (ok but not great), add code to functions.php, or install a plugin that enables this functionality.
This is the total code needed either in functions.php or in a separate plugin:
function enqueue_custom_scripts() {
// Enqueue the first script
wp_enqueue_script( 'botpress-inject', 'https://cdn.botpress.cloud/webchat/v0/inject.js', array(), '1.0', true );
// Enqueue the second script with the "defer" attribute
wp_enqueue_script( 'botpress-config', 'https://mediafiles.botpress.cloud/9223b195-3517-489e-b0cc-0bb9c7f72749/webchat/config.js', array(), '1.0', true );
}
add_action( 'wp_enqueue_scripts', 'enqueue_custom_scripts' );