These exercises can help you.
Añadido por Manar:
https://www.perfect-english-grammar.com/passive-exercise-5.html
Hafssa :https://www.curso-ingles.com/practicar/ejercicios/the-passive-voice
Samya H: https://www.superprof.es/apuntes/idiomas/ingles/gramatica-inglesa/clauses/exercises-passive-voice-in-present-simple-and-continuous-i-2.html
Samia M.