External Opt Out in AJO
Hi, I'm a little bit lost about how manage the third party unsubscription. I have my external landing page for unsuscbribe profiles (info.myexternalunsub.com/Email-Preference-Center.html?&optout=true).
So, I will create the message template in a journey and add "External opt out" type in Unsubscribe link

Then I can't understand the Subscription API Call, where and when the API call will be triggered? As the final unsubscription landing page (info.myexternalunsub.com/Email-Preference-Center.html?&optout=true) is hosted in an external tool I can't change anything there, neither the green unsubscribe button or the checkbox.
Here info.myexternalunsub.com/Email-Preference-Center.html?&optout=true template

Here I can see profile need to add its email so maybe third party tool will make all the work, matching email with opt out behavior but not sure about it.
So please if you can guide me step by step the API part and where that endpoint goes and so on as I can't understand very well the doc (https://experienceleague.adobe.com/docs/journey-optimizer/using/email/email-opt-out.html?lang=en#opt-out-external-lp).
Thanks!