The removed button is not what you think, it doesn't have any business related to the president's nuclear authorization or to alarm any emergencies, check here why Trump used that button.
However, there is one tradition that Trump did follow ahead of leaving office and that was, leaving a note to his successor Joe Biden in the Oval Office.
Speaking to the reporters in Oval Office, Biden said, "With the state of the nation today, I thought it's no time to waste, get to work immediately. There's no time to start like today".
After swearing-in, 78-year-old Joe Biden will become the oldest president of the US in its history while the 74-year-old outgoing President Trump is the second oldest.
Trump's advocacy for unity has come when he has become a symbol of insurrection, autocracy, and authoritarianism that has set the worst precedent in US history.
Along with Twitter, YouTube and Snapchat had permanently banned Donald Trump from their platforms for the same reasons while Facebook has banned Trump until the inauguration.