Is it obligatory to wear the hijab in front of maternal male cousins who grew up in the same house, knowing that they are treated as brothers and live in the same apartment, do not leave it, and the questioner does not work?

Your maternal uncle's sons are not among your mahram, and raising them with you and considering them brothers does not change the fact that they are non-mahram (strangers). Therefore, it is not permissible for you to appear before your adult maternal cousin without hijab, and likewise for the adolescent who is nearing puberty, according to the majority of scholars. You must speak to your father about this matter so that he can inform your maternal cousins of the Sharia ruling and teach them the etiquette of seeking permission.