问如何在POST请求中发送复选框值？

EN

    var mongoose = require("mongoose");

    var FriendGroupSchema = new mongoose.Schema({
        name: String,
        public_or_private: { type: String, enum: ["public", "private",] },
        friends: [
            {
                user: {
                    type: mongoose.Schema.Types.ObjectId,
                    ref: "friend"
                },
                admin: Boolean
            }
        ]
    });

module.exports = mongoose.model("friend_group", FriendGroupSchema);

<form action="/user/<%= user._id %>/newfriendgroup" method="POST">
    <% user.friends.forEach(function(selected_friend){ %>
        <p>--------</p>
            <div><img src="<%= selected_friend.user.profile_picture %>"></div>
            <div><h4><%= selected_friend.user.username %></h4></div>
            <h4>level: <%= selected_friend.level %></h4>
            <a href="/user/<%= selected_friend.user._id %>">more</a><br>
            <input type="checkbox" id="<%= selected_friend._id %>" name="<%=selected_friend._id%>" value="<%= selected_friend._id %>">
        <p>--------</p>
    <% }); %>
</form>