Odoo v11 process => stock.immediate.transfer

Question

I'm trying to process the reserved quantities of an order by API.

The same thing that I do by clicking here:

then here

but now working with API.

The reason why I'm trying with stock.immediate.transfer model is because before I only updated the stock.move model state to 'done', but I noticed that product remained in reserved.

So far I tried the following:

$common = ripcord::client("$url/xmlrpc/2/common");
$models = ripcord::client("$url/xmlrpc/2/object");

$picking_id = 3017;
$transfer_id = $models->execute_kw($db, $uid, $password,
'stock.immediate.transfer', 'create',
array(array('pick_ids'=>array($picking_id))));

print_r($transfer_id);
// here, an ID is returned, like 2205

$arr1 = $models->execute_kw($db, $uid, $password,
'stock.immediate.transfer', 'process',
array($transfer_id));

if ($arr1)
    echo 'is TRUE';
else
    echo 'is FALSE';

I tried the same as here

https://stackoverflow.com/questions/63674344/odoo-13-how-to-validate-a-delivery-order-with-api-python

but with no success. 'is FALSE' in printed, no error appears.

I don't know if this is the right way, I want to achieve this by code. I also tried

How to process 'stock.immediate.transfer' records on Odoo 15?

by adding

$picking_id = 3017;
$arr2 = $models->execute_kw($db, $uid, $password,
            'stock.picking', 'button_validate',
            array(array($picking_id))
        );
print_r($arr2);

but following error appears and after a long search I don't know how to fix it:

......... File "/usr/lib/python3.5/xmlrpc/client.py", line 519, in __dump raise TypeError("cannot marshal %s objects" % type(value)) TypeError: cannot marshal objects [faultCode] => 1 )

I'm using Odoo v11

Ripcord 0.9

PHP 7.4