Combine the water, vinegar, salt, peppercorns, and garlic in the bowl of the Instant Pot. Secure the lid and move the vent knob to the sealed position.
Select “Manual” and cook on high pressure for 1 minute.
While the Instant Pot is pressurizing, distribute the veggies into containers or jars with lids, such as Mason jars.
When the cooking time is up, carefully move the vent knob to “Venting” for quick pressure release.
Remove the Instant Pot lid and pour the vinegar mixture into the jars to cover the veggies.
Allow to cool for at least an hour before eating (the pickling will be partially done at this point), or close the lids and store in the refrigerator. The veggies will be completely pickled in 24 hours.