This works for me

1.Download https://github.com/ChillMagic/MPIR-Binary
2.Download https://github.com/AntonKueltz/fastecdsa
3.rename mpir.h to gmp.h from MPIR-Binary-master\include and rename mpir.lib to gmp.lib from MPIR-Binary-master\lib\MD\x64\Release
4.Copy and paste gmp.lib C:\Program Files (x86)\Microsoft Visual Studio\20XX\BuildTools\VC\Tools\MSVC\XX.XX.XXXX\lib\x64
5.Copy and paste gmp.h C:\Phyton3\include or C:\Users\XXXXXXXX\AppData\Local\Programs\Python\include
6.Open CMD and cd to where you put your fastecdsa E:\Download\fastecdsa-master
7.when your cmd is in the directory type: python setup.py build
8.after installation type again: python setup.py install