No such file or directory error when trying to build

I get fatal error: Arduino.h: No such file or directory when I try to build my project.
This is what my Platform.ini file looks like. I´m a little lost, and would appreciate some tips on what I should try/change. Thank you.

[env:nucleo_l031k6]
platform = ststm32
board = nucleo_l031k6
lib_deps = mbed-eduardog26/Arduino

No. That library is an mbed-os library that implements millis(), micros() and delay(). You’re trying to add it into a project that has no framework set (although this library would require framework = mbed).

If you just want to use your board with the Arduino framework, you’re on the completely wrong path. You just need the following content

and you can use #include <Arduino.h> normally. No lib_deps required.

Thank you so much for your help, I really appreciate it!