I also tried with latest SDK for iOS of Epson thermal Line printer for model TM-M30 still having same error screenshot attached here .
SDK link using in my iOS App as under;- https://download.epson-biz.com/modules/pos/index.php?page=soft&pcat=3&scat=58
So, I need proper help from anyone whoever use Epson Thermal line printer Intregation with SDK for iOS. Thanks in advance.