"Query.realEstateById" was defined in resolvers, but not in schema

Question

Facing an issue with nestjs graphql schema first app.

Error: "Query.realEstateById" was defined in resolvers, but not in schema. If you use the @Query() decorator with the code first approach enabled, remember to explicitly provide a return type function, e.g. @Query(returns => Author).

  my schema looks like: 
    # graphql
    # Root types
    extend schema
      @link(
        url: "https://specs.apollo.dev/federation/v2.0",
        import: ["@key"]
      )
    
    type Query {
      "Retrieve a Real Estate by ID"
      realEstateById(id: ID!): RealEstate
      "Retrieve Real Estate by User Id"
      realEstatesByUserId(userId: ID!): RealEstatesPayload # Use Connector
    }
    
    ## Complex and Value Types
    type RealEstate implements Id @key(fields: "id"){
      id: ID!
      userId: ID
      realEstateName: String!
      realEstateType: RealEstateTypeEnum
      purchasedOn: Timestamp!
      purchasePrice: Float!
      hasDebt: Boolean
      debtAmount: Float
      paymentRealEstateId: ID
      user: User
    }
    
    ## Interfaces
    interface Id {
      "enforces the usage of a global identifier which helps with other features"
      id: ID!
    }
    
    ## Enums
    enum RealEstateTypeEnum {
      RESIDENTIAL
      COMMERCIAL
    }
    
    ## Entities
    type User implements Id @key(fields: "id"){
      id: ID!
    }
    
    

resolver ---->

      @Query()
      async realEstateById(
        @Args('id', { type: () => ID }) id: string,
      ): Promise<RealEstate> {
        try {
          const realEstate = await this.realEstateService.getRealEstateByID(id);
          if (!realEstate) {
            throw new Error('Real estate not found.');
          }
          return realEstate;
        } catch (error) {
          throw new Error(`Failed to get real estate by ID: ${error.message}`);
        }
      }

Not able to get by facing this issue, things i have tried:

1. copyfiles - > in package.json "build": "nest build && copyfiles src/**/*.graphql dist/"