I couldn't find the field asin in the Catalog Items API documentation at this link:
https://developer-docs.amazon.com/sp-api/docs/catalog-items-api-v2022-04-01-reference
If this is the correct link, it seems that asin might not be a part of the request parameters. Since asin is a unique identifier for a product, if you want to retrieve information for a specific product, your request might need to look like this:
public function getOneProduct($productAsin)
{
$endpoint = '/catalog/v0/items/'.$productAsin; // Example endpoint for catalog
$params = [
'marketplaceId' => 'ATVPDKIKX0DER', // Example marketplace ID
];
return $this->makeApiRequest($endpoint, 'GET', $params);
}
Could you try making the request in this format? This method should allow you to retrieve information for a single product using its ASIN.
And for your all product :
public function getProducts()
{
$endpoint = '/catalog/v0/items'; // Example endpoint for catalog
$params = [
'marketplaceId' => 'ATVPDKIKX0DER', // Example marketplace ID
];
return $this->makeApiRequest($endpoint, 'GET', $params);
}
I hope this will be helpfull for your problem.