Auto generated String type @Id in Spring Boot to connect mongo

I am incrementing my Autogenerated Id value but I need String type

.This is my service class:

package com.stackroute.orderhistory.service;

import com.stackroute.orderhistory.model.AutogenerateId;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoOperations;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.core.query.Update;
import org.springframework.stereotype.Service;

import java.util.Objects;


import static org.springframework.data.mongodb.core.FindAndModifyOptions.options;

@Service
public class SequenceGeneratorService {
    @Autowired
    private MongoOperations mongoOperations;

    public String getSequenceNumber(String sequenceName){
        Query query=new Query(Criteria.where("order_id").is(sequenceName));

        Update update=new Update().inc("seq",1);

        AutogenerateId counter = mongoOperations
                .findAndModify(query,
                        update, options().returnNew(true).upsert(true),
                        AutogenerateId.class);

        return !Objects.isNull(counter) ? counter.getSeq() : "1";
    }
}

.This is my Entity Class :

import lombok.*;
import org.springframework.data.annotation.Id;
import org.springframework.data.annotation.Transient;
import org.springframework.data.mongodb.core.mapping.Document;

@NoArgsConstructor
@ToString
@AllArgsConstructor
@Getter
@Setter
@Document(collection = "orders")
public class OrderHistoryModel {
    @Transient
    public static final String SEQUENCE_NAME="Ordersequence";
    @Id
    private String orderId;
    private String productName;
    private int orderAmount;
    private String orderPlaced;
    private String orderStatus;
    private String paymentMethod;
    private String shippingAddress;
}

.This is my AutoGenerated Entity class :

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;

@Document(collection = "db_sequence")
@Data
@AllArgsConstructor
@NoArgsConstructor
public class AutogenerateId {

    @Id
    private String id;
    private String seq;
}

In this Code I am getting Order_Id as 1,2,3 and so on (In Postman)

But I need Order_Id like order1, order2, order3 and so on... Please help me out.