Signup on reactjs using axios - reactjs

Question

so i was trying to make a signup & login features on my web. My problem here is i cant post signup data to my api.
Here is the code that i make :
import React, { Component } from 'react'
import { Container } from 'react-bootstrap'
import { API_URL } from '../utils/constant';
import axios from 'axios';
import swal from 'sweetalert';
export default class Signup extends Component {
constructor(props) {
super(props);
this.state = {
};
}
handleSubmit = e => {
e.preventDefault();
const data = {
username: this.username,
password: this.password,
};
axios
.post(API_URL + "signup", data)
.then(res => {
swal({
tittle: "sukses",
text: "sukses",
icon: "success",
button: false,
})
}
).catch(error => {
console.log(error);
}
)
};
render() {
return (
<div className="signup">
<Container>
<div className="signup-page">
<form onSubmit={this.handleSubmit}>
<div class="mb-3">
<label>Username</label>
<input type="text" name="username" placeholder="username anda" class="form-control" onChange={e=> this.username = e.target.value} />
<div class="form-text"></div>
</div>
<div class="mb-3">
<label>Password</label>
<input type="password" class="form-control" onChange={e=> this.password = e.target.value}/>
</div>
<button class="btn btn-primary">Sign Up</button>
</form>
</div>
</Container>
</div>
);
}
}
My code here is not giving me any error, but the data is not post/added to my API.
i hope there is any suggestion from anyone of you because im just new into this reactjs,
this is my github link so maybe you might check it :
https://github.com/dannyambarita/Tubes_PWL/