Mac App Store converter for FLAC?
I recently pre-ordered a CD and was given the opportunity to download it in either of two quality levels. Intending to drag-and-drop into iTunes as I have with a few Amazon purchases (and as the site seemed to think I could do), I opted for the higher quality source to import to Apple Lossless. I've since learned of the curious fact that because it's FLAC it can't be opened directly into iTunes, but instead each track opens as a Quicktime file.
My question is, since I just want to convert the files into iTunes, should I get a conversion app (I would prefer one from the App Store and because I have iTunes I don't see the point in using another app to play or to stream) or should I just go back to the site and see if I can re-download it in the lower quality format (it didn't say what it was, I'm presuming it's compatible with Mac)?
Thanks to anyone who can recommend a process they've successfully used themselves.
iMac, macOS High Sierra (10.13.5), 27-inch, 1 TB, 3.2 GHz Intel Core i5