Kindly try to use as below:

declare @employeeData xml --this would be your XML input parameter

set @employeeData = '<employeeData>

<employee LastName="Smith" FirstName="Randolph" EmployeeID="1234567"/>

</employeeData>'

declare @xmlTable table (LastName nvarchar(255), FirstName nvarchar(255), EmployeeID int)

insert into...