Django ORM: Group by and Max

I have a model that looks like this:

Requests: user, req_time, req_text

In the DB, the records can look like this:

id, user_id, req_time, req_text
1     1      TIMESTAMP  YES
2     1      TIMESTAMP  NO
3     2      TIMESTAMP  YES

etc.

How do I write a Django ORM query that: groups the Requests by user, filters the Requests based on req_text, and also, select the max id of the resulting result set. So for each user, I will return one row which matches the filter condition and also has the greatest id.