For adding prefix to the option value
we can consider below example

// Define a custom function to be executed when the 'add_option' hook is triggered
function wpdocs_custom_add_option_action( $option, $value ) {
    // Perform custom logic or modifications to the option or its value
    // For example, let's add a prefix to the option value
    $modified_value = 'prefix_' . $value;
    
    // Save the modified value back to the option
    update_option( $option, $modified_value );
}
add_action( 'add_option', 'wpdocs_custom_add_option_action', 10, 2 );