Download the latest iTunes installer https://www.apple.com/itunes/download/win64
Grab Universal Extractor 2 and extract the zip. https://github.com/Bioruebe/UniExtract2/releases/download/v2.0.0-rc.3/UniExtractRC3.zip
Run UniExtract.exe and drag the iTunes installer onto the window. It should look similar to the following image.

Hit Ok and after extracting the installer you should be left with the following files/installers in the folder shown in the previous image.

Following the first image again drag iTunes64.msi into the extractor you should be greeted with another folder containing iTunes and System64 inside. You only want iTunes.
Depending on whether you're using portable mode OBS or an installed copy will determine where you will need to place the files.
Portable Mode (Default extraction without changes to anything) - OBS-Studio-31.0.1-Windows\bin\64bit
Installed Copy (Default path)* - C:\Program Files\obs-studio\bin\64bit
If you installed OBS to a location other than the default folder you can find the correct one by right clicking the OBS desktop shortcut and select open file location.
- ASL.dll
- CoreAudioToolbox.dll
- CoreFoundation.dll
- icudt62.dll
- libdispatch.dll
- libicuin.dll
- libicuuc.dll
- objc.dll