Hi guys,
I found the problem and it’s resolved.
While migration getimg.php file was not migrated.
So, after I uploaded the file, all images were generated automatically.
Because as most of you know, in getimg.php, class oxdynimggenerator is called and because of missing file,
I extended the class oxdynimggenerator in my own module but it was not called.
Thanks for your help!