If, by "rotation", you mean creating a new binlog, then decrease the value of
max_binlog_size. It defaults to 1G or 100M (depending on the version). 10M would have it creating smaller new files more frequently.
If you mean purging old binlogs, then set
expire_log_days (in old versions) to a small number, such as 1. Then binlogs older than 1 day will be deleted at some point.
In MySQL 8.0, it is
Added the binlog_expire_logs_seconds system variable, which sets an interval in seconds for purging of the binary log. The effects of this variable and expire_logs_days are cumulative, making it possible to set a period such as 1.5 days. To completely disable automatic binary log purging, set both variables equal to 0, which is the default value for both of them. (Bug #71697, Bug #18260088)
It is OK to change both the size and the expire. After changing the config file, restart the server.