OK I solved following the instrucion from here https://www.openstm32.org/tiki-view_forum_thread.php?forumId=7&comments_parentId=5300&threadId=8030&thread_sort_mode=commentDate_asc#threadId=8030
If still issue and expecting to target some other STM32 series let’s consider remote server address is always same : http://www.st.com/resource/en/firmware2Question
Then you have to complete such base address by firmware file name. Firmware fine names may be found within “your Ac6 SystemWorkbench for STM32 install path”\plugins\fr.ac6.mcu.ide_”id”\resources\board_def\stm32targets.xml file
Feel free to comment / share back !
So, basically check the xml for you board, like
I’ve put the zip in the folder
Now when you go for prj creation, the lib should be found.