Uncaught TypeError: login is not a function
at Object.submit [as fn] (eval at Yr (vue.min.js:7), <anonymous>:2:369)
at HTMLFormElement.<anonymous> (vue.min.js:6)

// register
Vue.component("login-form",
{
    template: // THE HTML FORM
,
    data: function () {
        return data;
    },
    ready: function () {
        this.isAuthenticated = this.checkIfAuthenticated();
        this.userName = localStorage.getItem("id_name");
    },

    methods: {
        checkIfAuthenticated: function () {
            const users = [
                {
                    id: 1,
                    name: "tom"
                },
                {
                    id: 2,
                    name: "brian"
                },
                {
                    id: 3,
                    name: "sam"
                }
            ];

            this.$set("users", users);
        },
        login: function () {
            const headers = { "Content-Type": "application/x-www-form-urlencoded" };

            $.ajax({
                url: "/token",
                type: "post",
                data: `username=${this.login.username}&password=${this.login.password}`,
                headers: headers,
                success: function (data) {
                    console.info(data);
                },
                error: function() {
                    this.isValid = false;
                }
            });
        }
    }
});
// create a root instance
var vue = new Vue({
    el: "#loginForm"
});

<form action="" method="GET" v-on:submit.prevent="form_submit">
    <input type="text" name="text" id="text" v-model="text">
    <input type="submit" value="submit now">
</form>

new Vue({
  el: 'body',
  data : {
    text : '',

  },
  methods: {
    form_submit: function() {
        var live_add = "{{ route('testdata') }}";
        var access_token = "{{ csrf_token() }}";
        this.$http.post(live_add, { client_name: this.text, _token : access_token  } ).then((response) => {
            console.log(response.data.client_name);
        }, (response) => {
            // some error callback
        });
    }
  }
});