Creating one to one Navigation Property without foreign key

Question

I am trying to query a table using navigation property from another table. The data has a shared key (like a foreign key) however it is not specified that way in the database. Entity framework core however gives me a The foreign key must target a type that is part of the relationship error. So my question is, how can I declare a navigational property for a one to one relation and use it as such?

public class ParentEntityConfiguration : IEntityTypeConfiguration<Parent>
{
    public void Configure(Entity TypeBuilder<Parent> builder)
    {
        builder.HasKey(e => e.InvoiceNumber); 
        builder.ToTable("Parent");
        builder.Property(e => e.InvoiceNumber).HasColumnName("InvoiceNumber"); 
        builder.Property(e => e.InvoiceGroup).HasColumnName("InvoiceGroup"); 
        builder.HasOne(e => e.Child).WithOne(x=>x.Parent).HasPrincipalKey("InvoiceGroup").HasForeignKey("AccountNumber");
    }
}
public class Parent
{
    DbContext _dbContext;
    public Parent(DbContext dbContext)
    {
        _dbContext=dbContext    
    }
    public string InvoiceNumber {get;set;}
    public string InvoiceGroup {get;set;}
    public Child Child {get;set;}
}
public class ChildEntityConfiguration : IEntityTypeConfiguration<Child>
{
    public void Configure(Entity TypeBuilder<Child> builder)
    {
        builder.HasKey(e => e.Id); 
        builder.ToTable("Child");
        builder.Property(e => e.Id).HasColumnName("Id"); 
        builder.Property(e => e.AccountNumber).HasColumnName("AccountNumber"); 
    }
}
public class Child
{
    DbContext _dbContext;
    public Child(DbContext dbContext)
    {
        _dbContext=dbContext    
    }
    public string Id {get;set;}
    public string AccountNumber {get;set;}
    public Parent Parent {get;set;}
}

StackTrace:

You are configuring a relationship between 'Parent' and 'Child', but have specified a foreign key targeting 'InvoiceGroup'. 
The foreign key must target a type that is part of the relationship.
at Microsoft.EntityFrameworkCore.Metadata.Builders.ReferenceReferenceBuilder.HasPrincipalKeyBuilder(EntityType principalEntityType, String principalEntityTypeName, Func`2 hasPrincipalKey) 
at Microsoft.EntityFrameworkCore.Metadata.Builders.ReferenceReferenceBuilder.HasPrincipalKeyBuilder(EntityType principalEntityType, String principalEntityTypeName, IReadOnlyList`1 foreignKeyPropertyNames) 
at Microsoft.EntityFrameworkCore.Metadata.Builders.ReferenceReferenceBuilder`2.HasPrincipalKey (String principalEntityTypeName, String[] keyPropertyNames) 
at Models.Data.Config.ParentEntityConfiguration.Configure(EntityTypeBuilder`1 builder)