I watched a YouTube. Cut a bend silicone straw. While emerged in water, use a clean hand to hold the straw. Put the straw into LO mouth and release the pressure to let the water out.
After that let LO suck to let water out. Eventually my LO got it. She’s drinking well from straw. Not so much from cup alone 😅
Should be able to find the YT video or I can share when I find it.