You have the wrong database name, go into the space and add the database name of your website and try it. Or did not create a database user, create a user, and then add to the database, it's ok

Correct installation is:

Database host: localhost Generally localhost

Database user: ******

Database password: *********** database already exists. Whether to overwrite! (red font)

Data table prefix: dede_ If there is no special need, please do not change

Database name: dedecmsv56gbk information is correct

Database encoding: GBK LATIN1 only for 4.1 + version of MySql to choose

Database user:

Database password: database already exists!