Darth Vader is one of the most powerful and insidious villains in Star Wars canon. Fewer antagonists are more memorable than this wheezing, fallen Jedi. However, he never once in the main films uses Force Lightning, the iconic weapon of Sith throughout canon. Palpatine, as seen in The Rise of Skywalker, can channel Force Lightning powerful enough to short-circuit a legion of starships. Against the entire Rebel Alliance, Palpatine stands above them all as a force of pure wickedness and hostility.
However, Vader has potentially even stronger Force powers than Palpatine, as seen by his manipulation of an even stronger, mightier Force Lightning. Although this was never seen in the films, it was revealed in the Marvel comics.
Red Lightning
Force Lighting comes in multiple forms. Most often, Lightning manifests as either white or blue-hazed energy that can bombard and overwhelm any and all targets placed before a Sith. Rey, Dooku and Sidious generate forms of Force Lightning like this. However, there is a third variety seen only by the most dangerous masters of the Dark Side: Red Force Lightning.
Red Lightning was a technique first mastered by Darth Rayze. Unlike normal Force Lightning, Red Lightning is generated by a Dark Side individual gathering and releasing cosmic energy of the universe itself. It can also be used to suck the life out of a target.
In Star Wars: The Clone Wars, the Son manifests Red Lighting to use as a weapon. The Son exists as an embodiment of the Dark Side, possessing a stronger link to the Dark Side than even the average Sith. His use of Red Lightning symbolizes his intense connection to that dark power. The Son is virtually immortal, with only the death of his father -- also known as the Father -- being enough to make him vulnerable to Anakin's lightsaber. Red Lightning, it appears, can only be manifested by the most powerful and dangerous individuals.
Vader Uses Red Lightning
Darth Vader physically cannot use Force Lightning. He has access to Force Lightning-esque abilities, such as Kinetite, but that is not the same thing as true Force Lightning generated within the spirit.
While in the Legends canon, this was due to how his robotic limbs cut him off from the greater Force, in the main canon, Vader using true Force Lightning will short circuit his life support and kill him. This is how he died in Return of the Jedi, when Palpatine's Force Lightning bombarded his life support. However, in the new canon, Vader can use Force Lightning, though only in astral projections of himself.
In Marvel's Darth Vader: Dark Lord of the Sith #25, while he is situated at Mustafar, Vader sends an astral projection of himself through a portal at his castle. Beyond the veil of this reality, he encounters multiple visions of Padme, with his access blocked by none other than Palpatine. While in this form, Vader generates Red Lightning to subdue Palpatine, scorching him off his path as he progresses to Padme.
This Red Lighting is manifested through Vader's raw, Force-projected body; it represents the Force potential within Vader. Had Vader not been on life support and vulnerable to the powers of his own Force Lightning, he could have demonstrated comparable -- or even more powerful -- Force abilities than Palpatine. The spirit was more than willing. Vader's powers, however, were simply too mighty for his body to handle.