Target log not found in binlog index. How to remove MySQL binary logs?

Question

MySQL

Hello.
/var/lib/mysql/ has accumulated a lot of binary logs like mysql-bin.000001 ... mysql-bin.000207 with large sizes. Enabled log rotation in my.cnf expire_logs_days=4 . Restarted mysql, executed the flush logs command; but nothing was removed. But I noticed that the old logs remained until a certain date. The new logs rotate like normal.
I want to delete old logs. I used these commands and as a result nothing was deleted. I dug up an interesting topic about the mysql-bin.index file.
Now it has the following contents:
./mysql-bin.000206
./mysql-bin.000207
Could this mean the reason why the logs are not deleted through the mysql command?
I want to remove mysql-bin.000004 but it is not listed in the mysql-bin.index file. Maybe because of this we get the error Target log not found in binlog index?
Who faced such problem?

Answer 1

It is done like this (mysql command)
purge binary logs before now();