EntityFramework.Functions library implements Entity Framework code first support for stored procedures (with single result type, multiple result types, output parameter), table-valued functions (returning entity type, complex type), scalar-valued functions (composable, non-composable), aggregate functions, built-in functions, niladic functions, and model defined functions.
Done with d9f80b302bdc9a74e14911326109bb200a151b1d, fe6c3df2097a5815e72e4e6aaa0ad7c7b292d1e0, 518283529d3adb8e2a220b8b2001ef205c2205a2. Please update your NuGet package.
Could you please add support for Entity Framework 6.3/6.4 on .Net Standard 2.1 targets?
If you don't have time, I can probably do it myself and create a pull request.