I have spent days just looking for any kind of instruction on how to play and found nothing. Why buy one if no one can begin to teach you how to play it?
Hey there! To answer your question, the lyre is an ancient instrument found in various parts of the world, mainly ancient Greece. If I were to guess, there were probably a lot of guides for how to play it, just in book form in the home language of the places it was commonly found in. 3 years later after yo0ur comment, the lyre has gained a ton of worldwide attention (mostly due to viral video games such as Genshin Impact and Hades featuring it) so there are a lot of different people making guides on youtube on how to play it, so if you're interested in it now, there's no better time to get started!