Under the Qt 6 site of Using OpenSSL Libraries with Qt for Android the CMake example for ANDROID_EXTRA_LIBS is incorrect and doesn't work. I suggest it should be something along the lines of:

set_property(TARGET ${PROJECT_NAME} PROPERTY QT_ANDROID_EXTRA_LIBS
    "<path_to_libs_dir>/libcrypto_1_1.so;\
<path_to_libs_dir>/libssl_1_1.so")