Oracle Instant Client 19.3 for Microsoft Windows (x64) 64-bit is available from OTN.
Oracle Instant Client comprises tools, libraries and SDKs for building and connecting applications to Oracle Database.
I had a few comments here about 19.3 that you may want to check.
Oracle Call Interface
Oracle XML Developer's Kit (XDK)
Oracle C++ Call Interface supports:
Compilers based on Microsoft Visual C++ 2017 Update 6 or later and Intel C++ 17.0 Update 8 with Microsoft Visual Studio 2017 STLs
The following component is supported only with Microsoft Visual C++ 2013 Update 5:
Pro*C/C++ : Use Microsoft Visual C++ 2013, to convert the Pro*C/C++ files into C/C++ files, and then use Microsoft Visual C++ 2017 Update 6 or later to further build them.