I am a new player in Typo3 and I have an issue with backward compatibility.
I was developing my personal extension using typo3 version 6.1 platform, and pack it into .zip file. This is possible since Typo3 version 6.1 can accept both .zip and .t3x files when it comes to uploading extensions using Extension Manager. There are no methods to download my extension into .t3x format.
The thing is, now I am working on different site using Typo3 version 4.5, and I would love to use my extension again. Since there are no method whatsoever in Extension Manager to upload .zip extensions, the only option for me is then to convert .zip to .t3x format.
Is there any possible ways for me to do this? Or am I missing some documentations about different work around?