proxy_users - column FLAGS

Oracle Database 19c Enterprise Edition - Version 19.18

RAC database on Oracle Linux

We have some employee users that have granted proxy .

Q1. When I query the table proxy_users, the FLAGS column shows two different values as below. What does each means?

1. PROXY MAY ACTIVATE ALL CLIENT ROLES

2. PROXY MAY ACTIVATE ROLE

when I give proxy to someone I run the following statement below. I don't give any option for the FLAGS column.

ALTER USER PHARMA_SANDBOX grant CONNECT THROUGH SPETERS;

Q2. How do I change the FLAGS column value ?

Thank you.