Let’s review the passage of Odin’s exile of Thor in the movie "Thor". After he exiled Thor, Odin also threw Thor’s Hammer on the earth. Before throwing the hammer, Odin cast a spell on Thor’s Hammer. The words are like this: No matter who gets Thor's Hammer, as long as he is qualified, he can have Thor's power.
Obviously, our Captain America has this qualification, which means that Captain America has the power of Thor, so of course he can also use the Storm Axe to summon lightning, but the American team can’t do without Thor’s Hammer. Or the Storm Axe can summon lightning.
So, when did Captain America possess the power of Thor? It was at the party in "Avengers 2". At this point, I have to admire the screenwriters of Marvel Pictures. It is not easy for them to make such a big game. At the beginning of "Avengers 2", the Avengers organized a party together after cleaning up the remaining party of Hydra, and everyone at the party took turns trying to pick up Thor's Hammer.
When it was Captain America’s turn, Captain America pulled Thor’s Hammer. I believe loyal Marvel fans must remember this segment, and the scene of Captain America pulling Thor’s Hammer was seen by Thor, so Thor from the beginning Knowing that Captain America has the qualification to pick up Thor's Hammer, in "Avengers 4" Thor saw the American team picking up Thor's Hammer and said the phrase "I knew it a long time ago."
Since the US team had the power of Thor early, why did he pretend to be unable to hold Thor's hammer? I think he doesn’t want to be too “high-profile”. The reason why Captain America can be recognized by Quake’s Hammer is precisely because Captain America has a pure heart of justice. He does not pursue fame or gain, nor does he love vanity, and he knows how to take care of it. Human feelings, so he didn't want to pick up the hammer in public to show off how different he was, and he didn't want to embarrass Thor, after all, Thor had just brag about it before everyone took turns trying to pick up the hammer.
In short, the US team had the power of Thor when they tried to pick up the hammer in "Avengers 2." Since he has the power of Thor, it is reasonable that he can use the Storm Axe to summon lightning.
