EF Core FK Constraint on Alternate Key

Hi I have an entity as below

public class SalaryTransactionAudit
{
      public long SalaryTransactionAuditId { get; set; }
      public Guid TransactionBatchId { get; set; }
      public DateTime UploadedDate { get; set; }
      public string UploadedBy { get; set; }
      public long SalaryTransactionStatusId { get; set; }
}

The above entity has primary key on SalaryTransactionAuditId and Alternate Key on TransactionBatchId as below

public class SalaryTransactionAuditConfiguration : IEntityTypeConfiguration<SalaryTransactionAudit>
{
        public void Configure(EntityTypeBuilder<SalaryTransactionAudit> builder)
        {
            builder.ToTable("SalaryTransactionAudit");
            builder.HasKey(e => e.SalaryTransactionAuditId);
            builder.HasAlternateKey(e => e.TransactionBatchId);
        }
 }

And I also have this entity

public class SalaryTransaction
 {
        public long SalaryTransactionId { get; set; }
        public Guid TransactionBatchId { get; set; }
        public long EmployeeId { get; set; }
        public int AnnualSalary { get; set; }
        public int SuperRate { get; set; }
        public int PaymentPeriodYear { get; set; }
        public int PaymentPeriodMonth { get; set; }

        public Employee Employee { get; set; }
   }

How do I configure (using fluent API) for FK Constraint on TransactionBatchId something like below

public class SalaryTransactionConfiguration : IEntityTypeConfiguration<SalaryTransaction>
{
        public void Configure(EntityTypeBuilder<SalaryTransaction> builder)
        {
            builder.ToTable("SalaryTransaction");
            builder.HasKey(e => e.SalaryTransactionId);
            builder.HasForeignKey(e => e.TransactionBatchId );

        }
}