Under GPL-like licenses you are obligated to provide source code if you provide a binary. If you don’t distribute anything, e.g. you only use something privately, then there are effectively no obligations. Of course, if you don’t provide source code for your project (whether legitimately or not), then by definition your project is not open source in the first place.

Note that the GPL specifically does not require publishing the source code, or having to distribute it along with the binaries. It allows the alternative of only providing the source code upon request by any third party, to that same third party.