With Drupal 8 / Drupal Commerce 2, I need to set default values in checkout / billing information. I need to get values from connected user fields.
How could I achieve this ? In Drupal 7 I did this implementing hook_form_alter and modifying $form, but in Drupal 8 billing informations is an entity (Profile) and I can't find where to put default values.
I feel like in hook_form_alter I could create a new Profile entity, set fields from user fields and then set this Profile entity as default value for the billing information form. Is this correct ?
There is a post about modifying the profile form (billing or shipping) in order to reload an old profile, set one as default or modifying an existing profile :
Unfortunately in my use case its useless : I allow only one billing profile, and I need to provide default values from user fields. But this will be be a great feature anyway.