Subscribes a lead to a specified sequence, at a particular step within the sequence. That step is defined by the step’s box number.
Note that the sequence and the step number must be already created in your account (https://app.kartra.com/communication/sequences).
* Required fields
Here is an example:
'actions' => [ '0' => [ 'cmd' => 'subscribe_lead_to_sequence_at_step', 'sequence_name' => 'Sequence name', 'step' => '1' ] ]