Proactive Messages with MS Teams Conversation Bot Node js (BotFrameWork v4)

I'm trying to send proactive messages at MS Teams, I based myself on a MS Sample that you can find at this Link and deploy in Dev BotFrameWork , now I want to provide the proactive messages like a separate service, in a HTML Form page for example, were I ll request from user a mesage and a email of who you want to send a message, and a text of the message, I tried to provide this function bellow like an path of my API, and call this when I recive a request from HTML page, at this particular sample, I'll only send messages to a restrict group of users, I have the MS TeamsID, tenantID and all channel data of each user stored at an MYSql DB.

But I don't know how to connect this to my Message Endpoint on Dev.BotFramework.

Can anyone help me at this?

note: This code works when I provide the email and text to the bot inside a teams conversation, but I want to provide this like a external service

async SendPrivateMessageAsync(context, who, text) {
    var dados = {}
    var membros = []
    const user = require('./sql').selectSingleUser
    who = who.replace(/\s*,\s*/g, ",")    who = who.split(',')
    for (var n in who) {        dados = (await user(this.poolConnection, who[n])
            .then(resp => {
                return resp[0]
            })
            .catch(err => {                console.log(err)
            })
        )        membros.shift()        membros.push(dados)
        const message = MessageFactory.text(`Aviso: ${text}`);
        var ref = TurnContext.getConversationReference(context.activity);        ref.user = membros[0];
        await context.adapter.createConversation(ref,
            async (t1) => {
                const ref2 = TurnContext.getConversationReference(t1.activity);
                await t1.adapter.continueConversation(ref2, async (t2) => {
                    await t2.sendActivity(message);

                });
            });
       await context.sendActivity(MessageFactory.text('All messages were sent'))
    }
    return true
}