Ciao @Paweł Kłos41 and thanks for your question. As far as I know, based on information from the Italian government, anyone age 12 and up whose most recent vaccination dose was more than six months ago starting from February 1 will not be eligible for a green pass unless they have a booster dose.
See more information at our article "Italy approves 3rd booster dose for all 12-15 year olds61" - which followed shortly after a decision to offer booster doses to all 16 and 17 year olds.