I want to inject Repository in Controller constructor using typedi

Question

I want to inject Repository in Controller.

Here is my FiedSettings Repository I have tried to follow typedi docs.

Field Setting Repository

import { Service, Container } from 'typedi';
import { Entity, PrimaryGeneratedColumn, Column, Repository } from 'typeorm';
@Service()
@Entity()
 class FieldSettings {

  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  name: string;

  @Column({default : false  })
  is_selected: boolean;

  constructor(payload: Record<string, unknown>) {
    Object.assign(this, payload);
  }
}
  Container.set('FieldSettings', FieldSettings);

export { FieldSettings };

FieldSettingsController

import {Request} from 'express';
import { getRepository } from 'typeorm';
import { IResponse } from '@interfaces';
import { success } from '@utils/common.util';
import { FieldSettings } from '@models/field-settings.model';
class FieldSettingsController {

    private static instance: FieldSettingsController;

    private constructor() {
    }

    static get(): FieldSettingsController {
        if (!FieldSettingsController.instance) {
            FieldSettingsController.instance = new FieldSettingsController();
        }
        return FieldSettingsController.instance;
    }
   
    async createFields(req: Request, res: IResponse): Promise<void> {
        try {
            const fields = new FieldSettings({
                name : req.body.name
            })

            await getRepository(FieldSettings).save(fields);

            res.status(200).json(success('', {}, res.statusCode));
        } catch (err) {
            console.log('err', err);
            res.status(400).json(success('', {}, res.statusCode));
        }
    }
}

const fieldSettingsController = FieldSettingsController.get();

export {fieldSettingsController as FieldSettingsController}

I tried to inject the repository

    @InjectRepository(FieldSettings)
    fieldSetRepo: Repository<FieldSettings>;
    private static instance: FieldSettingsController;

later i tried to work with it in createFields

 await this.fieldSetRepo.save(fields);

which threw error "Can't read undefined properties (reading fieldSetRepo)"

Please help me resolve this.