如何通过id将数据插入另一个表

I want to complete user sign up. firstly user will write username and password, table called users, I have id as primary key. secondly user will write address, phone number and zipcode, table called userdata, I have userid as index(key). I have did a relation between id from table user and userid from table userdata.

So now I want to insert data from php code I did two forms one for user and it has two input for username and password it works well and data inserted.

in the second form I have select option has id from table users and it works well. then in the same form I have three inputs phone number, address and zipcode. so the question is how I can insert the data to userdata by the same to the same id. so userid in table user will be the same id in table userdata.

I need sql code.
I used that : "INSERT INTO userdata(address, phone, zipcode) VALUE (:address, :phone, :zip) SELECT 'id' FROM 'users';"

First :

$q = "NSERT INTO users(username, password) VALUE ('Adam', '12345678')";
$r = $connect->query($q);

//get the last id u inserted 
$last_id =  mysqli_insert_id($connect);

Second :

  $q = "NSERT INTO userdata(address, phone, zipcode,user_id) VALUE ('California', '12345678', '1111','$last_id')";
    $r = $connect->query($q);

and if you want to make the (id) not the (userid) the same just :

$q = "NSERT INTO userdata(id, address, phone, zipcode) VALUE ('$last_id','California', '12345678', '1111')";
        $r = $connect->query($q);