The [ɾ] sound is not considered a distinctive sound in standard English, although it's found in some dialects of English. See notes below for a more detailed explanation.
Examples:
The IPA sound [ɾ] is known as the alveolar tap or flap. It's a consonant sound that is made by quickly tapping the tip of the tongue against the alveolar ridge, which is the bumpy area behind your upper teeth. It's a sound that is similar to the "tt" sound in the American English pronunciation of words like "butter" or "water."
The [ɾ] sound and the [r] sound in Brazilian Portuguese are similar in some ways but also have distinct differences.
The main difference between [ɾ] and [r] lies in the duration and the manner of articulation. The [ɾ] sound is quick and doesn't involve a prolonged vibration, while the [r] sound is longer and includes a rolling or fluttering motion of the tongue.
NOTES
The /ɾ/ sound is typically used when the letter "r" appears in the middle of a word and is followed by a vowel letter. You can hear this sound in words like "barata" (cockroach) or "Coração" (heart).