Touch the front of your tongue to the roof of your mouth, then release into a 'zh' position. Add vocal cord vibration.

Americans pronounce joey's as JOH-eez (/ˈdʒoʊiz/). Stress falls on the first syllable — keep everything else short and quick.
Record yourself saying "joey's" and play it back. The mic stays on your device — nothing's uploaded.
2 syllables, 4 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.
Stress falls on the first syllable, not the others. Stretch JOH — keep everything else short and quick.