如何使用jQuery延迟（当/然后等）来修复厄运问题的异步金字塔

I've been puzzling for quite a while trying to wrap my head around JavaScript promises. I want to fix some issues with asynchroneous calls in my code, to de-spagethise it. But I'd love for an expert to help me, because I've wasted quite some time already.I've been puzzling for quite a while trying to