Must probably that database was created when someone used a Microsoft Learn tutorial like this one to learn to use notebooks.
The best resort to answer who created that database and from what application name? is to enable Azure SQL Auditing, enabling auditing tracks database events and write them to audit log which can be stored into Azure storage account, Log Analytics workspace or Event Hubs.
Leverage the Log Analytics to retrieve and filter the Audit records, the following example is a Kusto Query to get audit data for the created database:
let ServerName = "XXXXXXXXXX"; # Change the Server name to Azure SQL Server name
AzureDiagnostics
| where LogicalServerName_s =~ ServerName
| where Category =~ "SQLSecurityAuditEvents"
| where statement_s contains "CREATE"
| project TimeGenerated, event_time_t, LogicalServerName_s, database_name_s, succeeded_s, session_id_d, action_name_s,client_ip_s, session_server_principal_name_s , database_principal_name_s, statement_s, additional_information_s, application_name_s
| top 1000 by TimeGenerated desc