error: undefined symbol

[Renio]

Goodmorning everyone,
i am starting to work with webassembly.
I describe my problem:
I have created a simple static library (called TinyLib), and I want to use in my WebAssembly project.
TinyLib contains contructor, destructor and a numeric attribute.
The WebAssembly project (called TestWidget) is a simple dialog with a label inside where I write through the TinyLib library.
My intent is to write the value of attribute into label.
I tried to compile both projects as Desktop mode projects (Desktop Qt 5.15.0 MinGW 64-bit) with success.
I compiled TinyLib with Qt 5.15.0 WebAssembly and generate libTinyLib.a lib
I compiled TestWidget, alon and the project run!
Now if I try to compile both projects in WebAssembly mode (TestWidget use TinyLib), while compiling TestWidget, I get this error message:

error: undefined symbol: _ZN7TinyLibC1Ev
warning: Link with -s LLD_REPORT_UNDEFINED to get more information on undefined symbols
warning: To disable errors for undefined symbols use -s ERROR_ON_UNDEFINED_SYMBOLS = 0
error: undefined symbol: _ZN7TinyLibD1Ev

I tried to search on the web but without success.
In this forum I found the following thread:
https://forum.qt.io/topic/115660/add-static-library
but it didn't help me.

Have you also had the same problem? And how did you solve it?

O.S. Windoows 10 Pro
Qt 5.15.0
EMCC 1.39.8

my pro file is

TestWidget.pro

QT += core gui

greaterThan (QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c ++ 11

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE = 0x060000 # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \
    dialog.cpp

HEADERS += \
    dialog.h

FORMS += \
    dialog.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:! android: target.path = /opt/$${TARGET}/bin
! isEmpty (target.path): INSTALLS += target

win32: LIBS += -L$$PWD/../../TinyLib/build-TinyLib-Qt_5_15_0_WebAssembly-Debug/ -lTinyLib

INCLUDEPATH += $$PWD/../../TinyLib/TinyLib
DEPENDPATH + = $$PWD/../../TinyLib/TinyLib

[Renio]

after contact the qt support, they suggest me to replace

win32: LIBS += -L$$PWD/../../TinyLib/build-TinyLib-Qt_5_15_0_WebAssembly-Debug/ -lTinyLib

with

wasm:LIBS += -L$$PWD/../../TinyLib/build-TinyLib-Qt_5_15_0_WebAssembly-Debug/ -lTinyLib