I would say most plants are safe, but here are some plants that make a good plants in a tree frog tank (copied and slightly edited from another topic):
Photos - They grow like crazy, sometimes a few centimeters a day. They are almost impossible to kill, thrive in frog terrariums and provide excellent climbing space.
Bromeliads: Air plants, so they do not need to be planted in the soil, but can be placed in the background or anywhere.
Snake plants: Extremly sturdy plants that provide excellent sleeping plants.
Creeping fig: Grows alot and provide alot of climbing space.
Ficus: Some have alot of small plants, other have fewer really big sturdy plants.