Um... Both «cachorro» and «roupa» would be pronounced as voiced uvular fricatives/trills (or whatever other realization depending on region, such as glottal/velar fricatives or voiceless uvular fricative/trill). However, single «r»s as in «chora» are pronounced as alveolar taps/flaps. At least, at the top of this discussion thread, the voice pronounces it correctly. Perhaps it was not pronounced as a tap before, in the exercise?
I'm Portuguese: R Sounds: R at the start of the word is pronounced like roupa or *cachorr*o. Two... Wait, see this article: https://en.wikipedia.org/wiki/Guttural_R#Portuguese