Default Subscription for Interactive Reports in Oracle Apex is Daily, Weekly and Monthly. Can we set it up for hourly/ by minute ?
I'm not in a position to test this, but it appears that hourly (but not "minutely") may be possible, but only via an unsupported route.
Subscription details are held in the APEX table called WWV_FLOW_WORKSHEET_NOTIFY, with the frequency in column NOTIFY_INTERVAL which is defined as VARCHAR2(1 BYTE). There is a constraint WWV_FLOW_WORKSHEET_NOTIFY_CK on this column defined as:
notify_interval in ('H','D','BW','W','M')
So it appears that at some point in the past hourly ('H') and bi-weekly ('BW') were permitted values. Of course, 'BW' is impossible as the column holds only one character.
So you could try updating this value in the table to 'H' and see what happens!