Solid starts and picky eating

So my three year old has always been a picky eater and the last year we've resorted to feeding her with a spoon to get her to have a few bites and using techniques like dessert only if you have a few bites. It worked for a bit but it's only making things worse now and I'm determined to change things somehow. The last week we've removed all pressure and follow a strict meal routine hoping it would help but she still literally won't eat. She had no lunch or dinner today at all.. anyways, I'm considering buying the "reverse picky eating" bundle on solid starts but it's so expensive and I'm honestly not sure what else they can suggest. I've read every post, blog, article about picky eating so I feel like I know a lot. Has anyone else purchased the course? Was it worth it!? Did it help!?

I'm also a bit confused because the founder has a 6 year old super picky eater named Charlie. But if she has a course called reverse picky eating why is her own son still a picky eater 🤔🤔🤔 like, does that mean there is no way to fix this? Then why would I buy the course in the first place. Please help, I'm so confused.