Lift your bottom lip so its inner edge (where the wet part meets the dry part) touches the very bottom of your top front teeth. Add vocal cord vibration as you blow air through.

Americans pronounce viewpoint as VYOO-poynt (/ˈvjuˌpɔɪnt/). Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "That is an interesting viewpoint that I had not considered before".
Record yourself saying "viewpoint" and play it back. The mic stays on your device — nothing's uploaded.
2 syllables, 6 sounds. Tap a syllable to jump to its row, then explore each sound's mouth shape and how it's made.
Lift your bottom lip so its inner edge (where the wet part meets the dry part) touches the very bottom of your top front teeth. Add vocal cord vibration as you blow air through.

Start with the tongue mid-front raised high, almost touching the roof of the mouth (but not touching). Glide into a tight lip circle as the tongue back lifts.
Press your lips together to stop the air, then release. No vocal cord vibration.

Start with rounded lips and tongue shifted back. Glide to relaxed lips with the tongue arching forward and up.
Touch the tip or front edge of your tongue to the roof of your mouth behind your teeth. Air flows through your nose.

Touch the tip or front edge of your tongue to the roof of your mouth just behind your teeth. Keep your jaw relaxed. Stop the air, then release with a puff.

The textbook way isn't wrong — it's just not how anyone actually says it.
Stress falls on the first syllable, not the others. Stretch VYOO — keep everything else short and quick.