In the example files I have downloaded, getting this error

[Choosetango]

System.DllNotFoundException: 'Unable to load DLL 'pdfium.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E)'

I noticed that the x86 and x64 folders didn't exist, so I added them, I still get the error. this is happening in the PdfiumViewer.Demo project.