Can a Monk use multiple Ki points to get more unarmed strikes from Flurry of Blows in a single turn?

In a recent session of 5e, our monk (4th lvl, way of Drunken Master) was using unarmed strikes, and the DM claimed that she could use any number of available Ki points to increase the amount of unarmed strikes granted by Flurry of Blows by an equal amount(spend 1 point to make 2 strikes, spend 2 points to make 3 strikes, etc.). I argued that since the Furry of Blows text says you can make two unarmed strikes as a bonus action, only one Ki point could be spent on this specific feature per turn. By RAW, how many strikes can be made in a single turn using this particular feature?