WHMCS Bridge WordPress plugin – Order loop [closed]

I post here, because for severals days, I’m trying to use the WHMCS Bridge plugin for WordPress and I’m encoutering an issue.

I think it’s maybe a misconfiguration of whmcs or wordpress.

This is my configuration :
Wordpress : 5.8.3
WHMCS Bridge : Free version 6.3
WHMCS : 8.3.1

This is my problem :

I configured the WHMCS bridge as following :

WordPress :

WHMCS URL   : https://whmcs.mydomain.com
Scope WHMCS CSS : checked
jQuery library : WHMCS
Load WHMCS style : checked
Load WHMCS invoice style : checked
Footer : Site

WHMCS (server) :

Company Name    My sweet company
Email Address   billing@mydomain.com
Domain  https://whmcs.mydomain.com
WHMCS System URL    https://whmcs.mydomain.com/
System Theme    : six
Maintenance Mode    Disabled
Friendly URLs Basic URL's

This is my problem :

When I visit my integrated store : https://www.mywordpress.com/whmcs-bridge/
And I select a product , I’m redirecting on /whmcs-bridge/?ccce=cart, and the order summary block is empty.

And when I click on the button ‘Continue / order’, I’m redirecting on :
https://www.mywordpress.com/whmcs-bridge/?ccce=cart&a=confproduct&i=2&systpl=six,
And visualy I have :

I have no idea to fix it . Could you help me ?