I have uploaded my file as a YML file, but I want to change it to a JSON file. Can I migrate the existing YML to a JSON file format?
Please note that Transifex cannot be used as a conversion tool in order to convert files from one file format to another. This means that the format you upload to Transifex is what you get after requesting the translation file. So, in order to achieve what you want, I would suggest you either create a script or use an existing converter (there are free tools that can offer you what you want).