Why did President Truman have a meeting at Potsdam in 1945?

The Potsdam Conference was held in the summer of 1945. Harry Truman, Joseph Stalin, Winston Churchill, and Clement Attlee attended it. One of the main purposes of this conference was to discuss what to do with Germany after World War II had ended.
The leaders reached several agreements about Germany and about Europe. They created a Council of Foreign Ministers. It included Great Britain, the Soviet Union, the United States, France, and China. They also agreed that an Allied Control Council would deal with the military administration of Germany. They agreed to have four zones of occupation. France, Great Britain, the United States, and the Soviet Union would have a zone that it would administer. Germany would be a demilitarized country. They also planned to try to develop Germany economically. The goal was to develop farming as well as developing industries that had no connection to military products, materials, or equipment. They also were going to put war criminals on trial. Germany would also pay reparations. There was some discussion about the border between Germany and Poland, but most of that was resolved after the war ended. However, Poland did get some land from Germany.
The leaders also agreed to issue an ultimatum to Japan to surrender without conditions. A little over a week after this ultimatum was issued, we dropped the first atomic bomb on Japan at Hiroshima.
There were many issues that were discussed at the Potsdam Conference.
https://history.state.gov/milestones/1937-1945/potsdam-conf

https://www.history.com/topics/world-war-ii/potsdam-conference