当我尝试通过动态导入进行导入时,“不是函数”

I have an mongoose model called car. Usually import it with

import car from "../../models/car";

我有一种情况,我想基于这样的变量导入特定的模型:

export default async function(req, res) {
  let category = req.body.category;
  let categories;

  const model = await import(`../../models/${category}`);
  categories = await model.default().aggregate([

  ...

}

我已经尝试过了,但是行不通。如果我使用旧的导入,它可以工作。有人可以告诉我这里的错误吗?