later on i found the solution for this, not sure if you still need it, keep a record here in case anyone else face the same issue.

Solution:
this was due to missing .net framework 3.5, just need to manually install .net framework 3.5 solve my compilation issue. Guess .net 3.5 only come with VS 2015 or older, VS 2017 onwards come with newer .net framework

That might have been better as a “black” code box,

Your definitely correct.

That might have been better as a “black” code box, as I was about to ask where to see PyInit_Npp

Only almost just before posting did I notice the scroll bar on the far right. :-)

Good info, though; I guess we all learned something.

@DGutierrez3
to make sure that the functions are exported you can use
a visual studio command prompt and call dumpbin /exports YOUR_PLUGIN.dll

something like

dumpbin /exports PySnack.dll

Microsoft (R) COFF/PE Dumper Version 14.16.27038.0
Copyright (C) Microsoft Corporation.  All rights reserved.


Dump of file PySnack.dll

File Type: DLL

  Section contains the following exports for Npp.cp37-win_amd64.pyd

    00000000 characteristics
    FFFFFFFF time date stamp
        0.00 version
           1 ordinal base
           7 number of functions
           7 number of names

    ordinal hint RVA      name

          1    0 00367360 PyInit_Npp
          2    1 003A4760 beNotified
          3    2 003A8F50 getFuncsArray
          4    3 003A7970 getName
          5    4 003A4660 isUnicode
          6    5 003A46E0 messageProc
          7    6 003A79F0 setInfo

  Summary

       5F000 .data
        D000 .pdata
       64000 .rdata
        3000 .reloc
        1000 .rsrc
      4C2000 .text

Forget about the PyInit_Npp, this is specific to my plugin but
the other 6 must be there.

And since your plugin contains that function, you should be easily able to set it to return true!

If you get back that this is an ANSI version then the call to IsUnicode does not return True.