Fatal error: Preferences.h: No such file or directory

Hello, i need help.
My project is not compiling.
#include <preferences.h> ends in fatal error: Preferences.h: No such file or directory.

i have this project structre:
src —> main.ccp
lib —> rfm.cpp, rfm.h

i need the Preferences.h inside ‘rfm.ccp’ so in included inside ‘Preferences.h’ and got the error when compiling.

but if i rightclick on
#include <preferences.h>go to definition
i can see the libary file Preferences.h
I also can see Preferences.h & Preferences.c under following paths:
C:\Users\xxx\.platformio\packages\framework-arduinoespressif32\libraries\Preferences.

in.vscode/s_cpp_properties.jsonunder 'include path i can see the line:“C:/Users/Christian/.platformio/packages/framework-arduinoespressif32/libraries/Preferences/src”,`

But the compiler/linker doesn’t find Preferences.h.
When i insert Preferences.h to the main.cpp, Preferences.h will be found.
what do i wrong?

thanks to all

Your directory structure is incorrect.
The README inside the lib directory clearly states:

The source code of each library should be placed in a an own separate directory …

Admittedly, the wording is misleading. It should read:

The source code for each library must be placed in an own separate directory.

All you have to do is create a new directory (e.g. RFM) within the lib directory and move your library files there:

|--lib
|  |
|  |--RFM
|  |  |--rfm.h
|  |  |--rfm.cpp

See also the documentation lib_dir — PlatformIO latest documentation

the whole example offers 2 options.
But nevertheless i tried all possible combinations.

i have no idea,why it runs after time.but i run again in this error with next lib.
i open a new thread,with dedicate example.

Both Bar and Foo are located in separate directories below lib.
The source code of Bar is located one level deeper in a src directory:

lib/Bar/src/Bar.c
lib/Bar/src/Bar.h
lib/Foo/Foo.c
lib/Foo/Foo.h

There are no
/lib/Foo.c
/lib/Foo.h