That base package is missing in the PlatformIO registry (basically PIO packaged version of https://github.com/STMicroelectronics/STM32CubeWL), that’s an issue in PlatformIO, similiar to Adding STM32CubeWB package to platformIO registry · Issue #686 · platformio/platform-ststm32 · GitHub but not yet tracked.
You could manually add that into platofrm-ststm32 by locally modifying ~/.platformio/platforms/ststm32/platform.json by adding the package to the list of packages
so e.g.
"framework-stm32cubewl": {
"type": "framework",
"optional": true,
"owner": "platformio",
"version": "symlink://C:/Users/user/Desktop/stm32cubwl"
},
where the path is pointing to a downloaded version of the STM32CubeWL repo with added package.json
of for example
{
"description": "STM32Cube is a set of tools and embedded software bricks available free of charge to enable fast and easy development on the STM32 platform (STM32CubeWL MCU Firmware Package)",
"keywords": [
"framework",
"hal",
"stm32",
"st"
],
"name": "framework-stm32cubewl",
"version": "1.26.2",
"homepage": "https://github.com/STMicroelectronics/STM32CubeWL"
}