usage of amplify w# binding

usage of amplify.fs

namespace Application2

open WebSharper
open WebSharper.JavaScript
open WebSharper.UI.Next
open WebSharper.UI.Next.Client
open WebSharper.UI.Next.Html
open WebSharper.JQuery
open WebSharper.Amplify


[<JavaScript>]
module Client =

    type Post = {
        UserId : int
        Id : int
        Title : string
        Body : string
    }

    type GetPostbyId = { Id : int }

    let log msg = JavaScript.Console.Log msg

    let Main () =
        
        /// https://jsonplaceholder.typicode.com/
        let getAll() =
            let settings = new AjaxSettings()
            settings.Url <- "https://jsonplaceholder.typicode.com/posts"
            settings.Type <- RequestType.GET
            settings.DataType <- DataType.Json
            settings.Cache <- true

            Amplify.Request.Define("getAllPosts", DefineRequestType.Ajax, settings) // DEFINE NOT FOUND

            let reqSettings = new RequestSettings("getAllPosts")
            reqSettings.Success <- (fun(data) -> log data)

            Amplify.Request(reqSettings)
            

        /// https://jsonplaceholder.typicode.com/posts/1
        let getById() = 
            let settings = new AjaxSettings()
            settings.Url <- "https://jsonplaceholder.typicode.com/posts/{id}"
            settings.Type <- RequestType.GET
            settings.DataType <- DataType.Json

            Amplify.Request.Define("getPostById", DefineRequestType.Ajax, settings)  // DEFINE NOT FOUND

            let args = new Object<string>( [|"id", "1"|] )
            Amplify.Request(
                "getPostById", 
                 args,
                 (fun(data) -> 
                    let data = As<Post> data
                    JavaScript.Console.Log(sprintf "title = %s" data.Title)
                    ()
                 ))

        (*  REST OF CODE GOES HERE .... *)
        let rvInput = Var.Create ""
        let submit = Submitter.CreateOption rvInput.View
        let vReversed =
            submit.View.MapAsync(function
                | None -> async { return "" }
                | Some input -> Server.DoSomething input
            )
        div [
            Doc.Input [] rvInput
            Doc.Button "Send" [] submit.Trigger
            hr []
            h4Attr [attr.``class`` "text-muted"] [text "The server responded:"]
            divAttr [attr.``class`` "jumbotron"] [h1 [textView vReversed]]
        ]