Prose poems often look like prose. They do not normally use line-breaks and are written in paragraphs rather than stanzas, e.g. in this Charles Simic poem.
However, they use other poetic elements like rhythm, rhyme, repetition, associative language, contortions of the sentence structure, and more.
It is hard to define what exactly a prose poem is! We encourage you to do your own research and make up your mind.