MariaDB drop partition gives syntax error - mariadb-10.2

Question

I try to drop partition in MariaDB database table by this command:
ALTER TABLE d_tracking DROP PARTITION 20151001;
but gets an error:
ERROR 1064 (42000): You have an error in your SQL syntax;
check the manual that corresponds to your MariaDB server version
for the right syntax to use near '20151001' at line 1
The syntax of the command is the same as on official page https://mariadb.com/kb/en/partition-maintenance/
"SHOW CREATE TABLE d_tracking" shows:
CREATE TABLE `d_tracking` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`idUser` int(11) NOT NULL,
`actionTime` datetime NOT NULL,
`action` varchar(255) NOT NULL,
PRIMARY KEY (`id`,`actionTime`),
KEY `idUser` (`idUser`),
KEY `actionTime` (`actionTime`)
) ENGINE=InnoDB AUTO_INCREMENT=28805509 DEFAULT CHARSET=utf8 ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=4
PARTITION BY RANGE (to_days(`actionTime`))
(PARTITION `20151001` VALUES LESS THAN (736237) ENGINE = InnoDB,
PARTITION `20160101` VALUES LESS THAN (736329) ENGINE = InnoDB,
...
PARTITION `od` VALUES LESS THAN MAXVALUE ENGINE = InnoDB)
Similar result for the command
ALTER TABLE d_tracking REORGANIZE PARTITION od INTO
( PARTITION 20220401 VALUES LESS THAN (TO_DAYS('2022-04-01'))
ENGINE=InnoDB, PARTITION od VALUES LESS THAN (MAXVALUE) ENGINE=InnoDB );
answer is:
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual
that corresponds to your MariaDB server version for the right syntax to use
near '20220401 VALUES LESS THAN (TO_DAYS('2022-04-01'))
ENGINE=InnoDB, PARTITION od VA' at line 1
Please help.
MariaDB server version is 10.2.24, OS Debian GNU/Linux 9.9.