Not really sure what you want or why. I suspect there’s a better way of doing what you really want.
But this might be what you asking about directly?
function f(; kwargs...)
arg = Symbol(kwargs[:argname])
println("value of argument named ", arg, " is ", kwargs[arg])
end
f(arg1 = 1, arg2 = "b", argname = "arg1")
f(arg1 = 1, arg2 = "b", argname = "arg2")