Dear M. Klosinski,
Please check with Soracom that the data plan included in your SIM includes NBIOT coverage. I have tried to find the information, but it is not so clear.
What is the country from where you perform your tests ?
Be aware that in the latest ST87M01 eval kit (EVKITST87M01-2 ), a SIM is included in the package, allowing plug-and-play evaluation (in Europe).
Concerning the configuration of the modem, you should install the startup package : STSW-ST87MGUI | Product - STMicroelectronics: It will install the GUI and it will create a folder (accessible from the GUI) with multiple docs and Application Notes inside (AT commands list, design guide, power supply recommendation, etc...), to guide you through the configuration of the modem depending on your application.
Best regards,
Didier Herrouin