Checkbox fields are not updated

[misaki-web]

Let's say we have a checkbox field in our Fluent form with the name statement. In the MailPoet integration feed, we associate this field {inputs.statement} with the corresponding one in the MailPoet form like this:

However, it'll fail. The new user is created but the checkbox statement is not checked in the MailPoet subscriber profile.

In its API documentation, MailPoet specifies:

If a custom field is a checkbox, send truthy or falsy value (true/false, 1/0 or "1"\"0").

If we associate fields with a truthy value as explained in the documentation, it'll work and the field with be checked in the MailPoet subscriber profile: