[QUESTION] What is the best way for an intermediate guitarist to learn guitar music theory?

I am self-taught and have been playing guitar on-and-off for 10+ years. I would say I’m pretty talented at this point, however I am very limited because I know nothing of music theory or how to improvise. For my fellow self-taught guitarists out there, how did you learn guitar music theory? Are there any specific resources that helped you?

Edit: Thank you all for the resources and encouragement! This has been very helpful for me and I hope for others as well. Decided to dust off the ol’ piano keyboard and get to work…