If any new customers register from the Portal and the ‘User approval’ flow is enabled from the “Customer Onboarding Validation Setting”, the admin will approve the portal user. After that, the registered customer can access the Portal.
You can approve the portal users (Contact) who is already portal user, but the Approval Status is “Pending”. By selecting the contact(s) from the list, you need to click on the Approve from the ‘Bulk Action’ drop-down options.
After selecting the “Approve” from the Bulk Action drop-down options, you need to click on Apply button.
Note: Only those admin users can approve the users that they have the access to do so.