Filtering data using different conditions on same column only filters data using the second condition

[samwata]

I want to filter data using two conditions from the same column.
For instance am filtering data when enumerator name is samwata or amwata from enumerator_name column using the following query.

https://api.ona.io/api/v1/data/531845?query={"$or":[{"enumerator_name":"amwata","enumerator_name":"samwata"}]}

This only filters data with enumerator name samwata only but it does not include data with enumarator name as amwata
I also tried to separate the conditions to different dictionaries but the result is the same

https://api.ona.io/api/v1/data/531845?query={"$or":[{"enumerator_name":"amwata"}, {"enumerator_name":"samwata"}]}