Follow the steps below:
1. Install Veeam ONE using a temporary database which will be created automatically once you start the installation. Make sure the database name is different from the default database name "VeeamOne" to avoid any conflicts with the original database in case it is located on the same SQL Server.
2. Change Veeam ONE database connection settings to connect previously created Veeam ONE database using Veeam ONE Settings Utility
3. Remove temporary created database using SQL Server Management Studio.