If i create USER custom details i can access and reuse them trough [[USER_CUSTOM_DETAILS_FIELD]] token for automation.

But if i create SUBSCRIPTION custom details i can't access and reuse them trough [[SUBSCRIPTION_CUSTOM_DETAILS_FIELD]] token for automation. What am i doing wrong?

I really need to collect a (unique) field for each order so trough SUBSCRIPTION, not USER.

Thanks.