Follow these instructions to get upload firmware into the SwitchBlox: note that this only has to be done once.
Open STM32CubeIDE application and open the workspace where the local copy of https://github.com/botblox/botblox-manager-firmware resides in.
Open the firmware project.
On the toolbar, select the Run button (highlighted on the screenshot below.

Select the Debug probe - SEGGER J-LINK.

Hold the 6 pin needly adapter in place, and click Run.
The firmware code should then upload to the SwitchBlox’s application memory.
Now the SwitchBlox can be configured using https://github.com/botblox/botblox-manager-software .