I need to limit the current when button is pressed and i off internal pullup resistors(use roff option). After i cann`t understand where i need to use in circuit external pullup for my task.
If I get it right, you want to turn off the internal pullup resistor of a GPIO and use an external pullup instead. External pullup has to be connected between the GPIO and VDD. Note that the Roff option has effect only on GPIO1 and GPIO2, both at the same time.