Buy (address buyer, address receiver, uint256 tokenAmount, uint256 point)
[topic 0]:0x89f5adc174562e07c9c9b1cae7109bbecb21cf9d1b2847e550042b8653c54a0e
[topic 3]:0x0000000000000000000000000000000000000000000000000000000000000000
0x00000000000000000000000000000000000000000000000000038d7ea4c68000