So, it’s actually a little more complex than it seems.
First. Make sure the model is right.
For the model you need the bones to all be consistent (same rotation).
To do this in blender you align the initial bone of the chanin, then select all the bones in the chain and the tip last. Witn fhe tip highlighted brighter orange you adjust fhe rotation of the other bones by deriving from the selected.
If you want to follow a tutorial, look for anything that is handling fingers / superfinger / superlimb alignment.
Second is the export.
Y forward, Z up.
Experimental apply transofrms so in case you forgot its covered.
Thid is the node/rig in engine.
On that, i cant help too much since im not sure what’s up.
Either use control rig or the abp with 2 bone ik.
Probably not both.
What you are seeing is definitely candy wrapper effect from a twist.
If the export has the correct (standardized among limbs) axis, then the engine shouldnt try to rotate the bones that way…