Nest can’t resolve dependencies in my project

the console says :
Nest can’t resolve dependencies of the VisitService (?, DonorService). Please make sure that the argument VisitModel at index [0] is available in the VisitModule context.

Potential solutions:

• If VisitModel is a provider, is it part of the current VisitModule?
• If VisitModel is exported from a separate @Module, is that module imported within VisitModule?

this is vistit.service :

import { forwardRef, Inject, Injectable } from '@nestjs/common';
import { InjectModel } from '@nestjs/mongoose';
import { Model } from 'mongoose';
import { DonorVisitStatus } from 'src/constants/donor-visit-status.enum';
import { GetDateDifferenceHours } from 'src/utils';
import { DonorService } from '../donor/donor.service';
import { VisitDocument } from '../schemas/visit.schema';
import { CreateVisitInput } from './graphql/visit.input';
import { Visit } from './graphql/visit.type';

@Injectable()
export class VisitService {
  constructor(
    @InjectModel('Visit') private readonly visitModel: Model<VisitDocument>,
    @Inject(forwardRef(() => DonorService)) private donorService: DonorService,
  ) {}

  async findVisitById(visitId: string): Promise<VisitDocument | undefined> {
    const visit = await this.visitModel
      .findOne({ _id: visitId })
      .populate('medicalCheckup')
      .populate('phlebotomy')
      .populate('donor');
    return visit || undefined;
  }

}

visit.module :

import { Module, forwardRef } from '@nestjs/common';
import { VisitService } from './visit.service';
import { VisitResolver } from './visit.resolver';
import { ConfigModule } from 'config/config.module';
import { MongooseModule } from '@nestjs/mongoose';
import { VisitSchema } from '../schemas/visit.schema';
import { DonorModule } from '../donor/donor.module';

@Module({
  imports: [
    MongooseModule.forFeature([{ name: 'Visit', schema: VisitSchema }], 'aidea_donation'),
    ConfigModule,
    forwardRef(() => DonorModule),
  ],
  providers: [VisitService, VisitResolver],
  exports: [VisitService],
})
export class VisitModule {}

i have checked it alot but i can’t find any error