Debounce and Pull-Up Resistors for Inputs from Encoder

By quick researching on the web, I found that pull up resistors for a rotary encoder (which type?) should be above 250 o and below 10 ko but 1ko is correct.
sheme on:

Assumed that is correct, there is still a problem I could not tackle because even with a validated code the count var remains to zero and also with a minimalist shematic without the capacitor. With a voltmeter, I found that, very scarcely, the pins have LOW values. They remain often on HIGH
(Arduino Playground - RotaryEncoders)

You might find this useful

or

if this is the type of encoder you have (you could post a photo) then pins clk & dt get connected to gound in the encoder, so MAY need pull-ups - unless they are already fitted to the module. Or you could just use input-pullup.

The value is not critical

Some of the encoder modules already come with necessary debouncing components. See the schematic in here: https://stm32f4-discovery.net/2014/08/library-26-rotary-encoder-stm32f4/
With raw encoders, you have to solve the problem yourself.