Raise the back of your tongue to touch the soft palate (velum). Stop the air, then release.

Americans pronounce counts as KOWNTS (/kaʊnts/). In "counts", the "t" is squeezed between other consonants and drops out — the surrounding consonants flow together without it — most natural in flowing, casual speech; in careful or formal speech, the T may be lightly present. This is called the Silent T in Clusters, and it's why Americans sound more relaxed than the textbook. It comes out as KOWNTS. You'll hear it in sentences like "The grand jury indicted him on multiple counts of embezzlement".
Record yourself saying "counts" and play it back. The mic stays on your device — nothing's uploaded.
1 syllable, 5 sounds. Explore each sound's mouth shape and how it's made.
Raise the back of your tongue to touch the soft palate (velum). Stop the air, then release.

Start with a dropped jaw and flat tongue. Glide into a relaxed, slightly rounded lip position as the back of the tongue stretches up.
Touch the tip or front edge of your tongue to the roof of your mouth behind your teeth. Air flows through your nose.

The T is skipped entirely. Your tongue doesn't make contact at the T position.

Place your tongue tip near the roof of your mouth behind your top teeth. Push air through the narrow gap. No voicing.

The textbook way isn't wrong — it's just not how anyone actually says it.
In "counts", the "t" is squeezed between other consonants and drops out — the surrounding consonants flow together without it — most natural in flowing, casual speech; in careful or formal speech, the T may be lightly present. /t/ is dropped entirely — the surrounding consonants flow together without the T.