How do I get my baby to drink water?

My 8 months old is struggling with drinking water. I would like her to start to get a few oz down a day to maybe help with some constipation. I have tried a small silicone open cup. She will take sips from it but then spits it all out. I have a small silicone sippy cup but she’s not really understanding how to drink from it. And when she does get some water…spits it out lol. Any advice? Other types of bottles or cups? I just am practicing with her everyday with meals but it doesn’t seem to be clicking yet.