With ADDR connected to the ground, the 8-bit I2C address would be 0x44 according to the datasheet.
There is no general approach, different devices use slightly different methods of setting the address, so you just have to read the description in each case.
In most cases there is a fixed part and a variable part. The whole address may be fixed, of course. If there is a variable part, then it is often just mapped to the address pins.
In this case they use 4 possible connections of the ADDR pin to define two variable bits of the address, allowing up to 4 devices on the same bus.