Unable to enter characters in MariaDB
If you are using Windows cmd, you need chcp 65001 before entering mysql/mariadb.  Since you are using a Linux variant, terminal may need SET NAMES utf8mb4; from within the mysql/mariadb.
If the columns are not utf8mb4, you will have other problems.  Check a table by using SHOW CREATE TABLE tablename;
This provides a rundown on common problems and leads to their solutions:  https://stackoverflow.com/questions/38363566/trouble-with-utf8-characters-what-i-see-is-not-what-i-stored