PHP - Variable To Array

Hey, im struggeling with a small piece of code....

Thats my code:

Global $user_ID;
$user_ID = get_current_user_id();

   echo"User number $user_ID is loggedin";

Echo gives me this:
"User number 2 is loggedin"

Now i want to add it to my array:
 

$atts['href'] .=  $user_ID . 'abc';

'href' is set to "https://test.com/"

What im getting now ist

https://test.com/abc

Can someone tell my why the '2' is missing??

I use a CURL script API with the header "$headers[] = 'Content-Type: application/json';"

The script ends with "$result = curl_exec($ch);"

If I simply echo the $result to  my browser, I get an array that looks like this:

stdClass Object
(
    [fromAddress] => stdClass Object
        (
            [name] => Fred Sender
            [phone] => 203-111-0000
        )

    [toAddress] => stdClass Object
        (
            [name] => Susan Recipient
            [phone] => 919-555-1212
            
What is the absolute minimum I need to do to access the phone number in the "toAddress" (919-555-1212).

Do I really need to "json_decode" this array?

I've spent 2 1/2 days trying every which way, with every permutation to access that one value:

echo $result["fromAddress"]["phone"];
echo $result->fromAddress->phone;
echo $result[0]->fromAddress->phone
echo $arr[0]->fromAddress->phone; // $arr = json_decode($result);
echo $arr->fromAddress->phone;
echo $arr[0]->fromAddress->phone;
echo $arr[0]->fromAddress["phone"];

Unfortunately I must have fallen asleep during the array lesson in PHP class  ?

Thank you.

array(1) {  ["84EA0353-58EB-E311-A8B1-001D09E7525D"]=>  
array(1) {    [0]=>    
object(stdClass)#7 (1) {      
["data"]=>      array(2) 
{        
["amt"]=>        string(7) 
"100.000"        
["unit"]=>        string(3) 
"BUC"      }    }  
}}

$x= $ArrayMap->amt;

$x= $ArrayMap['amt'];