Use request npm to create a http call.
request-promise —save npm I npm I npm I npm I npm I n
Create a folder called "services" and a file called "TextLocalSMS.js" for the class "TextLocalSMS.js."
var httprequest = require('request-promise');
module.exports = class TextLocalSMS {
constructor() {
}
async callApi(METHOD,URL,BODY){
    var options = {
        method: METHOD,
        uri: URL,
        headers:{
             'Content-Type': 'application/json',
             'Cache-Control': 'no-cache'
        },
        json:true
    };
    
    let response= await httprequest(options).then((result)=>{
        console.log(`SMS API: ${URL} RESULT =`,result);
        return result; 
    }).catch(function (err) {
        console.log(`SMS API: ${URL} ERROR =`,err.message);
        return err;
    });
    return response;
}
async sendSMS(toNumbers,rawMessage){
    let url = 'https://api.textlocal.in/send/';
    let sender = encodeURIComponent('TXTLCL');
    let encoded_message = encodeURIComponent(rawMessage);
    let body={
        apikey:'API_KEY',
        numbers:toNumbers.join(','),
        sender:sender,
        message:encoded_message
    };
    let result = await callApi('POST',url,body);
    return result;
}
}
Now require this file when you want to use it , suppose in app.js
var TextLocalSMS = require('./services/TextLocalSMS');
app.get('/demo',async (req,res)=>{
     // add logic for get user's phone nubmer from database here 
     // ...
     let otp = Math.floor(100000 + Math.random() * 900000);
     let text_msg = `MyWebsite.com -  OTP : ${otp} for reset your account password .`;
     let toNumbers = ['918123456789'];
     let smsService = new TextLocalSMS();
     let smsSent = await smsService.sendSMS(toNumbers,text_msg);
     // database query to store OTP with user_id in your database if otp successfully send to user 
     // ...
     return res.json(smsSent);
})