Example usage of block bindings

block-bindings.php

<?php

register_block_bindings_source('my-custom-prefix/current-year', [
    'label' => __('Current year', 'my-custom-prefix'),
    'get_value_callback' => 'my_custom_prefix_current_year',
]);


function my_custom_prefix_current_year()
{
    return date('Y');
}