Short answers, pulled from the story.
The Treaty of Finckenstein was an alliance concluded between France and Persia on the 4th of May 1807 at Finckenstein Palace, now located in Kamieniec, Poland. Napoleon I guaranteed Persian territorial integrity and promised arms, officers, and workmen to Fath Ali Shah in exchange for Persia declaring war on Britain and expelling British nationals.
The treaty was signed at Finckenstein Palace, a location now known as Kamieniec in present-day Poland. The palace gave the treaty its name, which is also commonly spelled Finkenstein.
Napoleon guaranteed the integrity of Persia and recognized Georgia, other parts of Transcaucasia, and Dagestan in the North Caucasus as Fath Ali Shah's possessions. He also committed to making all possible efforts to restore those territories to Persia and to supply the Shah with arms, officers, and workmen.
France failed to achieve diplomatic success in Persia and none of the treaty's provisions were fully implemented. Critically, just two months after signing the treaty, France concluded the Treaties of Tilsit with Russia, effectively abandoning Iran in its struggle against Russian expansion and undermining the alliance's core promises.
On the 12th of March 1809, the United Kingdom signed its own treaty with Persia that forced the French out of the country. This came less than two years after Finckenstein and ended French influence in Persia.
Persia agreed to declare war against the United Kingdom, expel all British nationals from Persian territory, and maintain an open passage for France if it wished to attack British possessions in the Far East. These obligations formed Persia's side of the Franco-Persian alliance.