Showing IPN handshake invalid

Hello,

We’ve setup Payment gateway on WHMCS through WHMCS document and after We’ve completed the payment gateway, We are receiving error in gateway log .
WHMCS support team guided us to connect to WP bridge plugin to set the url for gateway. Below is the message from them.

I am looking over this and I see that the Notification URL is set to the following:

https://xxx.xxx/client-area/?ccce=cart/modules/gateways/callback/paypal.php
That URL goes to your WordPress installation, not your WHMCS installation. The proper Notification URL should be:

https://xxx.xxx/support/modules/gateways/callback/paypal.php
It looks like the issue you are experiencing is being cause by the “WP Bridge” plugin you are currently using. Unfortunately, we do not develop this plugin and as such are not able to provide support for any issues encountered during its use. You will need to contact the developer of the plugin you are using so that they can investigate why the Notification URL is not being properly set, or how you can get it to redirect to the proper Notification URL on your installation.

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Now it is showing IPN handshake invalid.

Can anyone please guide me.

Thank You