How do I properly insert multiple rows into PG with node-postgres?

Use pg-format like below.

var format = require('pg-format');

var values = [
  [7, 'john22', 'john22@gmail.com', '9999999922'], 
  [6, 'testvk', 'testvk@gmail.com', '88888888888']
];
client.query(format('INSERT INTO users (id, name, email, phone) VALUES %L', values),[], (err, result)=>{
  console.log(err);
  console.log(result);
});