When you have more than one work by the same author in the same year, identify each source with a letter (a, b, c, etc.) after the year. This numbering applies to both the in-text references and the reference list entry, for example:
In-text:
The ABS reports that unemployment increased (2019a) while wages decreased (2019b).
Reference list:
Australian Bureau of Statistics. (2019a). Australian unemployment report. https://xxxxx
Australian Bureau of Statistics. (2019b). Australian wages report. https://xxxx