How to create a submission counter?

May you help me how to make submission counter from 123001 upwards?

You can make use of a Unique ID widget on your form. By this, you can set a submission counter that you can control and start from 123001 as desired.

You can check this guide to know more about the widget and how to set it up: https://www.jotform.com/help/79-How-to-Add-Custom-Unique-IDs-to-your-Form-Submissions

If you have questions, please let us know.