Go to Vault Settings > Admin Quorum. You see the default quorum for general approval of vault actions and also a list of quorums for each vault action. The default admin quorum can be edited - see Set the admin quorum.
The first time you access this page, all the vault actions use the default quorum. To customize a quorum for a specific vault action, click Manage Quorums, then click Edit on the quorum you want to customize.
Default uses the admin quorum you set for general approval of vault actions.
Custom enables you to change the number of admins and select specific admin users.
Auto approval is not always an available option, depending on how sensitive the action is. When available and selected, any request that meets the preset rules is automatically approved without waiting for additional admin review.
Select the quorum type and then select the number of admins, and, optionally, select who they are. Click Update to save the changes.