When using mysqldump:
mysqldump -u root -p database_name > backup.sql
You can get the error from the title
use --no-tablespaces
mysqldump requires at least the SELECT privilege for dumped tables, SHOW VIEW for dumped views, TRIGGER for dumped triggers, LOCK TABLES if the –single-transaction option is not used, and (as of MySQL 8.0.21) PROCESS if the –no-tablespaces option is not used. Certain options might require other privileges as noted in the option descriptions.
and see documentation of param no-tablespaces
–no-tablespaces, -y
This option suppresses all CREATE LOGFILE GROUP and CREATE TABLESPACE statements in the output of mysqldump.
Fix:
mysqldump -u root -p database_name > backup.sql
--no-tablespaces