Why my contact can’t marketable ( receive email )

I have saved the contacts from the website using API, the contacts are automatically tagged and go to the email sequence, but the contact’s emails have not been received because of not permission marketable, so how can I automatically allow marketable my contact?

When you use the api to save the contact to IBK/Keap, you have to run the optin method on the contact’s email address afterward with the api.