I am updating the post I wrote below (about 30 mins ago) as I have discovered that the Beta (mentioned in my original post) is likely to work correctly. The reason I am encountering the issues I described (the absence of selectable values within a mandatory field) is most likely related to the fact that we have not yet connected the WhatsApp account in our HubSpot account.
Unfortunately, I haven't been able to do this yet because I'm waiting for the purchasing department to provide me with the SIM card with the new number. It's highly probable that once we connect the WhatsApp account, the Beta will function correctly, and if that's the case, I believe the problem can be considered resolved.
has anyone managed to solve the problem related to the inability to manage WhatsApp opt-ins through a workflow?
In my use case, the "reluctance" to use the manual method is not so much due to having a large database but rather because we would like to be able to send a WhatsApp message automatically once a Contact has filled out a form (provided that they have given consent to be contacted via WhatsApp in the form).
The workflow we would like to create is not a "one-time" workflow to mass-update WhatsApp subscriptions for all Contacts. Instead, it's a workflow that, triggered by any form submission, would check through an if/then condition if the Contact has given consent to receive WhatsApp messages, and only if that's the case, it would send a message using a template.
However, when I try to use it, I notice that at a certain point in the workflow action settings, I'm asked to fill in the "Communication Subscription Type" field, and there's no value to enter. However, the field is mandatory, so I can't complete the action setting (see attached screenshot).