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

Americans pronounce corporate as KOR-per-uht (/ˈkɔrpərət/). Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "Our corporate retreat is in the mountains".
Record yourself saying "corporate" and play it back. The mic stays on your device — nothing's uploaded.
3 syllables, 6 sounds. Tap a syllable to jump to its row, then explore each sound's mouth shape and how it's made.
The textbook way isn't wrong — it's just not how anyone actually says it.
In "corporate", the "t" is not released — the articulators get into position but hold without the burst of air. Air stops but there's no release burst — the articulators hold position.
Stress falls on the first syllable, not the others. Stretch KOR — keep everything else short and quick.
Don't pronounce the second syllable too fully. The unstressed syllable reduces to a schwa — the lazy "uh" sound — in casual speech.
Americans use a relaxed retroflex R — the tongue curls back rather than rolling. The R is one continuous sound with the vowel before it, not two separate sounds.