If he were going to the inauguration, Democrats would be trying to prevent him attending. And some congressional Republicans too.
According to Fox News:
“President Trump is expected to travel to his resort at Mar-a-Lago in Florida the morning of Jan. 20 – the day of President-elect Joe Biden’s inauguration – where he is expected to reside after his presidency, Fox News has learned.
“No official announcements have been made, but Fox News has learned that Trump’s tentative plan is to depart the White House that morning and travel to his Palm Beach resort.
“Fox News has learned that the president is also expected to bring a number of staff members with him, including personal assistant Nick Luna; Cassidy Luna, his wife and a deputy assistant to the president; Molly Michael, who currently serves as Oval Office operations coordinator; Cassidy Hutchinson, the director of Legislative Affairs; and press aide Margo Martin.
“The president announced last week that he would not attend Biden’s inauguration, in an extraordinary move, making him the first to skip the inaugural ceremony of his successor since 1869.”