The CUBE files provided on purchase of LUTx can be used in many other programs. For Adobe Premiere Pro and After Effects you can load them using the Lumetri built in effect. Lumetri is under video effects, color correction in both PPro and AE.
The CUBE files in LUTx collections are designed to be applied on clips in rec709 color space and for best results you should make sure that the footage is neutral, eg that it has good white balance, exposure, temperature and tint. For best results you can use the White Balance and Tone controls before the "Creative" section of Lumetri.
If your clip is shot in a log color space such as Slog2 or Blackmagic Film log then you should use the correct camera LUT first in the "Input" section of Lumetri to convert to rec709. After applying the LUT for a base look, then tweak the other exposure and color balance settings as desired.
Hope this helps, please contact us if you need more information.