Error when importing QGC in Qt creator for the first time

When attempting to open Qgroundcontrol on Qt Creator, I have this issues :

  • C:\Qt\5.15.2\msvc2019_64\mkspecs\features\toolchain.prf:76: error: Variable QMAKE_CXX.COMPILER_MACROS is not defined.
    -error: Project ERROR: msvc-version.conf loaded but QMAKE_MSC_VER isn’t set
  • error: Error while parsing file D:\Dev\QGC\qgroundcontrol\ Giving up.

P.S I followed the qgroundcontrol developer guide to setting up my environment.
Thank you for any help!
Best Regards,