enabled-managed-backup-all-databases.sql

-- Define the variables
declare @databases table (rowid int identity primary key, dbname varchar(500))
declare @rowid int, @dbname varchar(500), @sql varchar(2000)

-- Get the database names from the system function
insert into @databases (dbname)
select db_name
  from msdb.smart_admin.fn_backup_db_config (null)
 where is_managed_backup_enabled = 0
   and is_dropped = 0

-- Iterate through databases
select @rowid = min(rowid)
  from @databases

while @rowid is not null
begin
    set @dbname = (select dbname From @databases Where rowid = @rowid)
    begin
        set @sql = 'exec msdb.smart_admin.sp_set_db_backup @database_name= '''+'' + @dbname+ ''+''',
                    @retention_days=7,@credential_name=<credential_name>,@encryption_algorithm = NO_ENCRYPTION,@enable_backup=1;'
        execute (@sql)
    end

    select @rowid = min(rowid)
      from @databases
     where rowid > @rowid
end