Option 1: nRF Connect for VS Code (recommended)

1. Open the nRF Connect extension panel from the VS Code activity bar.
2. In the application picker, select the Browse nRF Connect SDK add-on Index option.
3. Search for Serial Modem Host Applications and create the project.

4. Click Add build configuration under the application entry to open the build configuration dialog. Set the Board target to the value from the Build targets table for your hardware.

5. Keep the other fields at their defaults and click Generate and build to build the application.

6. Flash the device.

   In the Actions panel, use Erase and flash to board for the first flash of a device. A plain Flash can fail on a device that has never been programmed with this application, or that is read-back protected. If it does, run west flash --recover once from the nRF Connect terminal, then continue using the extension.

   Note: Erase and flash to board (and --recover) wipes TF-M Protected Storage, so any installed nRF Cloud device credentials are lost and must be provisioned again. For routine re-flashing during development, use the plain Flash action to keep the credentials in place.

   For nRF91M1 setups, two development kits are connected at the same time. When prompted for which device to flash, select the debugger ID of the host DK (nRF54L15 or nRF54LM20B), not the nRF9151 Serial Modem DK.

7. After flashing, open a serial terminal on the host console port to view the device logs. The Serial Terminal app (part of nRF Connect for Desktop) is recommended; PuTTY, Tera Term, and minicom also work. The console port depends on the board — see the application guides.

8. Follow the application guides for hardware setup and cloud onboarding for the respective application.

For more details on how to use nRF Connect for VS Code, refer to the nRF Connect for VS Code documentation.