Yes you can program your telegram bot and send any message using javascript (using AJAX since the telegram bot api is a web request based api).

For example, you send message to a specific user by this:

let tg = {
    token: "BOT_TOKEN", // Your bot's token that got from @BotFather
    chat_id: "CHAT_ID" // The user's(that you want to send a message) telegram chat id
}

/**
 * By calling this function you can send message to a specific user()
 * @param {String} the text to send
 *
*/
function sendMessage(text)
{
    const url = `https://api.telegram.org/bot${tg.token}/sendMessage?chat_id=${tg.chat_id}&text=${text}`; // The url to request
    const xht = new XMLHttpRequest();
    xht.open("GET", url);
    xht.send();
}

// Now you can send any text(even a form data) by calling sendMessage function.
// For example if you want to send the 'hello', you can call that function like this:

sendMessage("hello");

Also you can use POST request to send data. For example:

let tg = {
    token: "BOT_TOKEN", // Your bot's token that got from @BotFather
    chat_id: "CHAT_ID" // The user's(that you want to send a message) telegram chat id
}

/**
 * By calling this function you can send message to a specific user()
 * @param {String} the text to send
 *
*/
function sendMessage(text)
{
    const url = `https://api.telegram.org/bot${tg.token}/sendMessage` // The url to request

    const obj = {
        chat_id: tg.chat_id, // Telegram chat id
        text: text // The text to send
    };

    const xht = new XMLHttpRequest();
    xht.open("POST", url, true);
    xht.setRequestHeader("Content-type", "application/json; charset=UTF-8");
    xht.send(JSON.stringify(obj));
}

// Now you can send any text(even a form data) by calling sendMessage function.
// For example if you want to send the 'hello', you can call that function like this:

sendMessage("hello");

For more information see telegram bot api documentation: https://core.telegram.org/bots/api

Sorry for my bad English. Anyway, I hope this helps :)

You can use the Telegram API to send messages.