Hello @sk-ys
currently PbHub does not support internal pull-up/pull-down resistors. See FAQ at the end of the documentation page here. I assume the same is true for EXT.IO2.
Note: I have no idea if there are plans to support this feature in the future.
BTW: I faced the same issue a while ago and I resorted to adding some 10 k SMD resistors to the inputs.
Thanks
Felix