Most plants for the aquarium will be axolotl friendly, its just axolotl’s aren’t necessarily plant friendly
they will dig them up if they are not secured by a pots or suction cups. Also axolotls require cold dimly lit water, where the vast majority of aquarium plants like well lit warm water. This limits your options substantially, however beautiful planted axolotl tanks do exist, but they have a light. If you do want an aquarium light for your plants, make sure you have lots and lots of dark places in your tank for your axolotls to hide. Some axolotls seem to react to light more than others, so if you did want a light, make sure to test out your axolotl’s reaction to it. Mine HATE it, they freak out, but I have hear others who have been quite successful with them.
a few well adapted low light/heat plants do exist as stated above, the java family is great... java moss and java ferns are extremely hearty and will survive fine in an axolotl friendly environment, they also look great! Pennywort and Duckweed are good floating plants, but duckweed grows out of control fast and gets everywhere! Pennywort is hard to find in Aust but not sure about the US and i have never had hornwort experience.
Axolotls do like fake plastic plants a lot too; they do not seem to notice the difference. They will even lay on them. Most people keep plastic ones because its easier, but live plants if you can manage them help with water quality.