[Jewbacca]

I (kinda) think I’m right:

https://www.verywellhealth.com/best-foods-to-eat-for-resistant-starch-4000028

(Point 11)

[ConservativeMind]

You might do better to get the whole bean, but the supplement you referenced is “White Kidney Bean Extract,” so its goal is to get rid of components that don't block other carbs from being utilized. Specifically, this extract gets rid of all substances in the white kidney bean but the special compounds, described in this study:

It's No Has Bean: A Review of the Effects of White Kidney Bean Extract on Body Composition and Metabolic Health

White kidney beans (Phaseolus vulgaris L.) possess three isoforms of α-amylase inhibitors—α-AI1, α-AI2, α-AIL [25], with the α-AI1 isoform shown to inhibit amylase activity in mammals [26]. The structure of α-AI1 is a classic lectin fold, containing no α-helices and a plethora of antiparallel β-sheets [23].

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7284421/

So that capsule is filled with three amylase inhibitors white kidney beans are fortunate to have, but not the fiber or resistant starch or the carb components.

Hope this helps.