Quick question, doesn’t your source material (i.e., the videos you are trying to use the LR extension on) have both sets of subtitles available on it? (English and Spanish.)
For example, if the video only has English CC, then the LR extension cannot provide you with Spanish subtitles.
It’s a tricky limitation I have been trying to navigate since not many YouTube videos have English and Korean CCs. (Note: I’m learning Korean.)
However, I did notice (as a Pro User) that some of the videos (the videos that—at the very least—have Korean CC only) can have English translations (probably due to the machine translation feature Pro users have:
