Error Invalid type for column time, must be of type timestamp or unix timestamp, got: string

Hi All

need your help i got respon error “Invalid type for column time, must be of type timestamp or unix timestamp, got: string”

when query datasource with postgress timeseries.

my queries like below :
indent preformatted text by 4 spaces
SELECT to_char(create_date, ‘YYYY-MM-DD HH24:MI’) as time,count(1) FROM tbl_transaction where create_date > NOW() - INTERVAL ‘15 Minutes’ and order_type=‘PURCHASE_AIRTIME’ group by time ORDER BY time ASC;
indent preformatted text by 4 spaces

could you help to solve my case ?

Thanks
FAjar