Blend the cashew and the water in a high powered blender. No need to soak the cashews.
Add in the agar powder and the sweetener, blend again for a few seconds.
Pour the mixture in your Instant Pot.
Warm it up using the Keep Warm function. It will take about 30 minutes. Alternatively, you could do it faster on the stovetop or in the Instant Pot using the Sauté function. You want the temperature to reach 110-115F. I don't use a thermometer, I just feel it. It should feel slightly warmer than body temperature.
Add your probiotic capsules. Four capsules should be enough.
Turn off your Instant Pot, unplug it, and wrap it in a towel.
Keep it wrapped for 24 hours.
Unwrap and pour the yogurt in a Mason Jar.