@Valentin Rosca​ There is an API to create new dashboard object but also it is not recommended by Databricks as it is mentioned "Databricks does not recommend designing dashboards exclusively using this API." Please refer below:

https://docs.databricks.com/sql/api/queries-dashboards.html#operation/sql-analytics-create-dashboard

Also, The widgets field on a dashboard is read-only. As of now, we cannot design new widgets and create them with the API as it is not supported.