No amount of bribery or sternness will cure school related anxiety.
That's a very big generalisation. On the topic of resilience, most people feel relieved and slightly prouder of themselves if they pushed through a situation made them anxious. Children's minds are simpler and if they associate attending a day of school with a positive reward at the end of the day or week, then than alone is often enough to reframe the experience for them. It's basically CBT and exposure therapy. By conquering something they want to avoid (with added incentives like toys or whatever) then they feel slightly more capable of coping with the same situation again.
And this works with ND kids as well, albeit dependant on level of severity. People here are using autism and neurodiversity like be all and end all argument. If a child is proven ND then their brains can't possibly adapt to a neurotypical environment. I will get lots of hate for saying this but I daresay they do. Look up neuroplasticity and the theory of post traumatic growth. I believe that neurodivergent children with lower support needs can benefit from being in a school where they are treated the same as everyone else but also have the benefits of finding friendships with like-minded kids and experiencing all the "core memories" that are a vital part of childhood. Birthday parties, school events, school dances, being part of a sports team, contributing to school publications, having crushes, first dates etc.
One can argue those are vital parts of the human experience. Virtually all songs, TV shows, movies and literature are built around core elements of social interaction. A key complaint of ND people is that they feel left out in groups and always "different" or lonely or hated that they felt like others didn't like them. However they still innately crave connection, often more intensely than NT people. I can't think of anything more detrimental than a ND child who gets taken out of school and spends all day on their phones consuming content created about human interaction, but never ever getting to experience it themselves. It's condemning them to a life of being an observer and always being on the outside looking in.
Again, well aware that if school refusal has worsened to the point of hysteria and physical then this isn't possible. But a key role as a parent would be to build up the social structure of school so the child genuinely enjoys being there for things other than just learning. Play dates, contact with other parents, volunteering, parties, PTA whatnot. Don't think it's a coincidence that kids who thrive most at school tend to be the children of PTA mums or kids of teachers who have that inner circle where everyone knows each other.