Calling a Dynamic Multicast Delegate in BP

Hello,

I have in a class A a declared Dynamic Multicast Delegate such as

    DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnReadyToBind_Delegate);
    UPROPERTY(BlueprintAssignable)
    FOnReadyToBind_Delegate OnReadyToBind{};

I have a class B that inherits from A.

And in an other class MyGA (a GameplayAbility) I call

myAObject->OnReadyToBind.AddDynamic(this, &MyGA::Bind)

This compile successfully.

But Now, in an instance of B, declared in Blueprint, I wish to call/to execute the OnReadyToBind delegate.
The editor does not let me do so, I can assign to, bind to, unbind event, unbind all, but I can not call.

Am I missing something ? Did I not understand how to do use delegates ?

Thank you very much <3