I have installed a module that allowing to upload attachment to products. But I have to do this pro-grammatically via my other custom module. installed module have API function in it. But I don’t know how to call these API function in Magento-2.

As API file Api/ProductAttachmentRepositoryInterface.php have function –

public function save(Data\ProductAttachmentInterface $ productAttachment);

And respective file at location Data/ProductAttachmentInterface.php have following code . That have some variable declaration, get/set function.

`namespace Companyname\ProductAttachment\Api\Data;  interface ProductAttachmentInterface {     const ID = 'id';     const PRODUCT_ID = 'product_id';     const FILE_PATH = 'file_path';     const FILE_NAME = 'file_name';     const FILE_URL = 'file_url';     const FILE_SIZE = 'file_size';     const FILE_TYPE = 'file_type';      const FILE_TYPE_FILE = 'file';     const FILE_TYPE_URL = 'url';      const CUSTOMER_GROUP = 'customer_group';     const STORE_CONFIG = 'store_config';      const CONTENT = 'content';      public function getId();       public function getProductId();      //public function getFilePath();       public function getFileName();public function setId($  id); ` 

Here I am bit confuse…..what I need to pass as parameter and which function I should call and how ?

Please help me on this…