How to update sequence number to a existing table that contains data

Question

CREATE TABLE e_demo_tab (
    e_id     NUMBER(10),
    e_uuid   NUMBER(10),
    seq_cnt  NUMBER(10)
);

INSERT INTO e_demo_tab VALUES(11,13,null);
INSERT INTO e_demo_tab VALUES(11,13,null);
INSERT INTO e_demo_tab VALUES(11,14,null);
INSERT INTO e_demo_tab VALUES(11,14,null);
INSERT INTO e_demo_tab VALUES(12,15,null);
INSERT INTO e_demo_tab VALUES(12,15,null);

I have one table e_demo_tab wherein I have to update the seq_cnt column based on the e_uuid column. If for the same e_id example for 11 we have e_uuid column as 13 which is appearing two times so the seq_cnt should be updated to 1 and 2 respectively and likewise for the same e_id i.e 11 for e_uuid 14 again it should update the count as 1 and 2 respectively. I am wondering if this can be handled using row_num or not. Please suggest.

Expected Output:

+------+--------+---------+--+
| E_ID | E_UUID | SEQ_CNT |  |
+------+--------+---------+--+
|   11 |     13 |       1 |  |
|   11 |     13 |       2 |  |
|   11 |     14 |       1 |  |
|   11 |     14 |       2 |  |
|   12 |     15 |       1 |  |
|   12 |     15 |       2 |  |
+------+--------+---------+--+