You can export tracks as wav files which Audacity can import. However, given Fairlight in Resolve is vastly more suited to audio editing and mixing, I'm perplexed as to why you would use Audacity? I regularly help people learn to make podcasts and I recommend they use Fairlight in Resolve and not Audacity which for me is an ordinary edit tool. I do use Audacity occasionally to make an mp3 file.
Fairlight is an amazingly powerful editor, with heaps of built in plugins, plus you can use VST plugins. It has very powerful EQ, processing and full automation including being able to sub bus signals to create stem mixes. Having track based, bus based and clip based processing, it really is the best audio system of any NLE