Looks like the Libreria Oracle ODBC Driver you have installed is badly linked or installed resulting in the Library not loaded: @rpath/libclntsh.dylib.12.1
error. It can possibly be worked around by placing all the Oracle instantclient files in the /usr/local/lib directory where the rpath is set to.
Note also OpenLink provide there own Oracle 12 ODBC Driver for macOS, which just works out of the box, as detailed in this post which show connection to Excel on macOS.