How to change the bound rate of Grove Triple Color E-Ink Display 2.13

According to the demo code in the wiki, Arduino should use bound rate 230400 to communicate with Grove Triple Color E-Ink Display 2.13.
But I want use Arduino mini pro which can not support high bound rate. Is there some method that can change the bound rate of Grove Triple Color E-Ink Display 2.13 to bound rate 115200?
Thanks!

Hi there! Thanks for your patience for waiting! Unfortunately, the bound rate of this product cannot be changed as it has been set at 230400.

And we highly recommend you using Arduino Uno or our Seeeduino baseboards for the higher outcome and we do believe they will definitely meet your needs.

Don’t hesitate to contact us if you need any help. Thanks.