How to replace multiple variable from file.txt

Question

Inside file form.txt

Name : $name

Gender : $gender

Age : $age

is my code to replace variable in form.txt

const fs = require('fs').promises;

var rForm = await fs.readFile(__dirname + '/form.txt', 'utf8');

var name = 'maman';
var gender = 'male';
var age = 10;

rForm.replace('$name', name);
rForm.replace('$gender', gender);
rForm.replace('$age', age);

console.log(rForm);

and is my result from my code

Name : $name

Gender : $gender

Age : $age

There is noting changed. The result I wanted is

Name: maman

Gender: male

Age: 10

How to change multiple variable in this case ??

I try this

const fs = require('fs').promises;

var rForm = await fs.readFile(__dirname + '/form.txt', 'utf8');

var name = 'maman';
var gender = 'male';
var age = 10;

var nm = rForm.replace('$name', name);
var gn = rForm.replace('$gender', gender);
var ag = rForm.replace('$age', age);

console.log(nm);
console.log(gn);
console.log(ag);`

and the result is

Name : maman

Gender : $gender

Age : $age

Name : $name

Gender : male

Age : $age

Name : $name

Gender : $gender

Age : 10

Answer 1

The replace() method returns a new string with one, some, or all matches of a pattern replaced by a replacement.

rForm = rForm.replace('$name', name)
             .replace('$gender', gender)
             .replace('$age', age);

console.log(rForm);

or

rForm = rForm.replace('$name', name);
rForm = rForm.replace('$gender', gender);
rForm = rForm.replace('$age', age);

console.log(rForm);