Modal verbs can be combined with the passive voice in Spanish, the same way as in English, e.g "He should be put in prison" or "I had to be taken to hospital."
The modal verb is conjugated in the required tense and then followed by "ser" + participle (agreeing with the subject).
Tener que (to have to)
Querer (to want)
Poder (to be able to)
Necesitar (to need)
Modal verb (conjugated) + ser + past participle (agreeing with subject)
Note that the passive voice is not as commonly used in Spanish as it is in English. Sometimes, to avoid the formal passive in Spanish, we find alternatives in the active voice or using the passive "se" construction.
For example for:
Las joyas perdidas no pudieron ser localizadas.
we could also say:
No se pudieron localizar las joyas.
Nadie pudo localizar las joyas.
without changing the original meaning of the sentence.