Not that I'm a guy who understands all of what it takes to pass something, but here are the only vetos Trump has issued. It seems to me Congress is the culprit.
President Donald Trump has issued the following vetoes:[1]
July 24, 2019: S.J.Res.38 - A joint resolution providing for congressional disapproval of the proposed export to the Kingdom of Saudi Arabia and the United Kingdom of Great Britain and Northern Ireland of certain defense articles and services.[2]
July 24, 2019: S.J.Res.37 - A joint resolution providing for congressional disapproval of the proposed export to the United Arab Emirates, the United Kingdom of Great Britain and Northern Ireland, and the Republic of France of certain defense articles and services.[3]
July 24, 2019: S.J.Res.36 - A joint resolution providing for congressional disapproval of the proposed transfer to the Kingdom of Saudi Arabia, the United Kingdom of Great Britain and Northern Ireland, the Kingdom of Spain, and the Italian Republic of certain defense articles and services.[4]
April 16, 2019: S.J.Res.7 - A joint resolution to direct the removal of United States Armed Forces from hostilities in the Republic of Yemen that have not been authorized by Congress.[5]
March 15, 2019: H.J.Res.46 - Relating to a national emergency declared by the President on February 15, 2019[6]