It's not healthy to have no sex drive. Something is wrong physically or emotionally.
My wife had a friend who didn't want to have sex with her husband and shut him off because she felt he sided with his mother over her. He was oblivious and had no clue what was going on. Women are complicated. Once they dealt with it, they were fine. Can you talk about it?
Women are also complicated hormonally. She might have something going on there. If she's open to it, have her seek out a doctor who specializes in it, even if they seem a bit woowoo. Again, it's not normal and healthy to have no sex drive.
Is she open to you trying to get her going with touch, perhaps with a vibrator? That's by far the most fun part of the whole experience anyway when she get going and has her orgasm. It's not close. After a year and a half I'm sure you just want release, but is she open to you trying to please her? I think if I just wanted a wham bam thank you mam my wife would just reluctantly let me do my thing like it's a chore.
My wife and I are going on 40 years together and that part of life is the best ever by far. Sounds weird but we are still getting more comfortable and less inhibited with each other. And we're post-kids and post ability to have kids. She's gotten some hormonal things straightened out and is as horny as she was as a newlywed. It was always good, but goes up and down throughout the stages of life, and now is on fire. Helps that she's smoking hot (I'm not).
I hope this is real and I haven't wasted time invested into helping you. She should be concerned about it. You should be talking about it like it's a serious illness that you two want to find a cure for.
Now maybe it's just not a part of her like some people have bad eyesight or are deaf or something and you just live with it, but the first thought should be that it's a problem that needs to be fixed.