Domain key issue facing

I installed the Litespeed cache plugin and when I tried to apply for the domain key it is showing the following error:
There was a problem with retrieving your Domain Key. Please click the Waiting for Approval button to retry.

There are two reasons why we might not be able to communicate with your domain::

1) The POST callback to failed.

2) Our Current Online Server IPs was not allowlisted.

Please verify that your other plugins are not blocking REST API calls, allowlist our server IPs, or contact your server admin for assistance.:

I already set all the settings from the security

How can I get rid of this error?

Can you please tell me if this is for 1 website or multi-website

and this plan is for caching and speed optimizing, I,m right

and in this plan, you're offering with Quick Cloud Services,Right sir