脚本的参考代码：

(async () => {
  let token = pm.variables.get("accessToken");
  console.log("当前token：", token)
  const getToken = async () => {
    const res = await pm.sendRequest({
      method: "post",
      url: "http://192.168.31.88:42224/api/v1/login",
      data: {
        username: "user2",
        password: "a123456"
      }
    })
    if (res) return res.data.accessToken;
  }

  if (!token) {
    console.log("未存在token，开始获取token")
    token =  await getToken().catch((err) => {
        console.log("err", err)
    });;
    pm.variables.set("accessToken", token);
  }

  // 判断token是否有效
  try {
    const res = await pm.sendRequest({
      method: "get",
      url: "http://192.168.31.88:42224/api/v1/project/list",
      headers: {
        authorization: `Bearer ${token}`,
      }
    })
    console.log("token有效",)
  } catch (error) {
      // 重新获取token
      console.log("token已失效，开始重新获取", error)
      token =  await getToken().catch((err) => {
          console.log("重新获取token失败", err)
      });;
      pm.variables.set("accessToken", token);
      console.log("重新获取token成功", token)
  }

  // 使用token
  pm.request.header.push({
    key: "authorization",
    value: `Bearer ${token}`,
  });
})()