Search like number field in MongoDb by NestJs

let aggregateTotal = [];
let aggregateMatch = {};
if (searchServiceDto.hasOwnProperty('code')) {
  Object.assign(aggregateMatch, {
    codeStr: new RegExp(searchServiceDto.code.toString()),
  });

}
aggregateTotal.push(
    {
      $addFields : {
        codeStr: {
          $toString: '$code'
        }
      }
    }
)
aggregateTotal.push({
  $match: aggregateMatch,
});
aggregateTotal.push(
    {
      $project : {
        codeStr: 0
      }
    }
)
let data = await this.serviceSoftModel.aggregate(aggregateTotal);

type code in MongoDb is number