Is it possible to unsubscribe a contact using the Form Submission API?

I’d like to be able to unsubscribe a contact from a subscription using the Form Submission API Does anyone know if this is possible?
I’m able to subscribe someone using the Form Submission API just fine but unsubscribing doesn’t seem to work.

I submit a Request body like the following

{
 "fields": [
 {
 "objectTypeId": "0-1",
 "name": "email",
 "value": "bob@example.com"
 }
 ],
 "legalConsentOptions": {
 "consent": {
 "consentToProcess": true,
 "text": "I agree to allow XXXXXXX to store and process my personal data.",
 "communications": 
 [
 {
 "value": "false",
 "subscriptionTypeId": "99999999",
 "text": "Opt In XXX."
 } 
 ]
 }
 }
}

I get a 200 response and a response body like this

{
 "inlineMessage": "Thanks for submitting the form."
}

BUt when I check the contact in Hubspot they aren’t unsubscribed to the relevant list.

Hey, @DMartin88 :waving_hand: To unsubscribe a contact, you’ll need to use the Subscription preferences endpoints. I understand what you want to do, and you’ll need to send a second call for the unsubscribe action.

Best,

Jaycee