The LCD is driven by a STM8S005C6 microcontroller. To access the SWIM pin header for programming, you have to open the case and scrape away some potting compound.
Programming using STVP works similar like at the TSZD2, just another MCU type (STM8S005C6): https://github.com/hurzhurz/tsdz2/blob/master/programming.md