If access denied errors are displayed when you try to import MySQL backup file via phpMyAdmin, most likely your MySQL query contains invalid (forbidden) queries.
Please open your MySQL file and make sure there are no queries like 'use database' or similar. Also make sure your MySQL file does not contain any MySQL database names/usernames/passwords (if a file is being imported from another host, most likely database name or username/password will be different here).
Your MySQL file should contain standard queries like CREATE TABLE and INSERT in order to work properly.
Find articles and information about all features, troubleshooting guides,
and other technical information on Hostinger's hosting services.