database upgrade issue from 10.3.39 to 10.11.5 - rds- mariadb

Hi Everyone,

can anyone please help me out here?

database upgrade issue from 10.3.39 to 10.11.5 - rds- mariadb

error: We're sorry, your request to modify DB instance testdb has failed. The AllowMajorVersionUpgrade flag must be present when upgrading to a new major version.