Do you still have the .apk file that was generated months ago?
If so, rename it to .zip extension, open it and have a look in your /assets directory.
Thanks for the update
But I used it build ipk
Is there are another way to get source code
do you mean an iOS ipa? you can also rename it zip and unzip it then click on the unzipped file and click "show package contents" and there you can grab the source in the www directory. (oh this is on a mac)