What will be the value of UNTIL property in the rrule stirng to have only 3 instance of the recurrence event

Question

let a recurrence event starts at 2023-08-05 09:30:00UTC and has localTimezone "Asia/Jeruslame" with rrule as "RRULE:FREQ=WEEKLY".

Considering the above situation, set UNTIL value for only 3 recurrence instance. I am using npm rrule package https://www.npmjs.com/package/rrule.

I tried RRULE:FREQ=WEEKLY;UNTIL=20230819T093000Z as rrule string and expecting to include 19 of Aug in the dates as last date of recurrence instance.