The [t] sound in English sometimes confuses English language learners when it appears at the end of a word. This is because it’s said very lightly.
I wouldn’t answer a question by saying
*”I don’t”
aspirating that “t” at the end of “don’t“.
But instead, I start to say the [t] sound by placing the tip of my tongue at the top of my mouth, just behind my teeth. However, I do not release and finish the [t] sound; I simply say the first half of it and hold my tongue against the top of my mouth without finishing the sound.
Practice with me, and hold the tip of your tongue at the top of your mouth just behind your teeth instead of finishing the [t].