Thanks a lot for your help, Jarnovos!
But maybe I haven´t explained properly, please apologize.
I do not need to influence on cookies loaded by the iframe, at least not directly.
I just need to retrieve the user aceptance value in order to concatenate to the iframe url. Of course, on the other iframe side, they will develop a logic in order to load or not load G.analytics scripts accordlingy to the value of parameter on the url.
So, basically, my question is: is there an existing shortcode that allows me to retrieve the user level consent? Something like [cookies-allowance] that provides a value to me to concatenate to the iframe url?
Thanks a lot!!