How can I explicitly disable the priority and the asignee when creating a ticket via the API?

To create a ticket without setting the priority or assignee, you should ensure that the priority and assignee_id fields are not included in the JSON payload of your API request. Here's an example of how you might create a ticket without setting these fields:

{
  "ticket": {
    "subject": "My new ticket",
    "comment": {
      "body": "The smoke is very colorful."
    }
    // Do not include "priority" or "assignee_id" here
  }
}

However, if after doing this, the tickets are still being assigned or the priority is being set, then you should check the following within your Zendesk instance:

1. Triggers: Look for any active triggers that automatically set the priority or assign tickets to a group when a ticket is created. You may need to adjust or deactivate these triggers.

2. Automations: Similar to triggers, automations can change ticket properties after a ticket is created based on certain conditions. Review any automations that might be affecting your tickets.