To run the Keepit G Suite backup you can have any of the G Suite editions - Basic, Business, or Enterprise. You must use an administrator account with access to data across all accounts to configure the backup. Please also make sure that API access is enabled in this account. To enable API, please see the following instructions: https://support.google.com/a/answer/60757?hl=en
It is also necessary to have the Keepit app installed in G Suite, which can be done through the G Suite Marketplace.