The case centres around articles in the newspaper that criticised Beijing’s leadership and supported the protests.
The demonstrations upended the city for months, with disruptions ranging from road blockages to serious clashes with police.
Lai said his articles had suggested solidarity with peaceful protesters, but that had not extended to supporting violence.
“We were trying to get them together with us, so their violence will be reduced,” Lai told the court.
Lai was also questioned about the founding of the English online edition of Apple Daily in May 2020, when the city was bracing for the security law.
Lai told the court a “sense of crisis” drove him to believe that the new edition would help Hong Kong by motivating foreign politicians to “take notice of our situation” and “voice out their concerns” to China.
Apple Daily was forced to close in 2021 after police raids and the arrests of its senior editors.
Lai has been behind bars since December 2020, and concerns have been raised about his medical and jail conditions.
He did not opt to testify in any of his five previous cases, all of which resulted in convictions, including for organising and participating in marches during the 2019 protests.