Read write Si7021 sensor

Please, help with example code of reading temperature and humidity from Si7021.

For instance. A command has been given to measure relative humidity. From the description it is clear that the command must be sent 2 times. The first command must be preceded by “Start (S)” and the second must be preceded by “Start Repeat (Sr)”. How can this be done using the rui_i2c_rw() function?