Unblock IP Address

I am using this code to block IP.
```php
$expression = "ip.addr eq $IP";
$config = new Cloudflare\API\Configurations\FirewallRuleOptions();
$config->setActionBlock();
$result = $firewall->createFirewallRule(
    $zoneID,
    $expression,
    $config,
    'Testing ip blocking'
);
```
---
How do i unlock this IP? Could anyone help?