The majority of the workflow for sending an Interim Certificate is performed via a 'screenflow' that can be launched from a course record page.
Access to this tool is restricted to users with the 'IsCan Send Interim Certificates' custom permission. If you believe you should have access to the tool but don't, please check in with the National Salesforce helpdesk.

From the record page of the course containing the students you wish to deliver an interim certificate for, navigate to the actions bar, select the drop-down arrow and click 'Send Interim Certificates'

The utility will identify which active 'Interim Certificate' products could be delivered for students on the originating course. This is done by comparing the competencies defined on the Interim Certificate products and the competencies contained in the product for the course.

Using the select box, select the Interim Certificate product you would like to send.

Once you have chosen a product, select 'Next'

The utility will identify which attendees on the originating course have met the requirements to receive the interim certificate by checking for 'competent' on each of the Interim Certificate's competencies, the 'paid' status and ensuring that 'Student USI Required' is not true.

The utility will then present a list of students that could receive the chosen Interim Certificate.
Using the checkboxes on the left of the table, select which students you would like to send a certificate to.

After selecting students, you can make the decision to send the 'employer copy' for any student that has given employer permission.
Set this toggle if you would like employer copies to be sent where possible, if you want to send student copies only, leave the toggle inactive.

Once you have set the toggle, select 'Next'

If 'Deliver Employer Copy' was selected but some of the chosen students have not given permission, a warning screen will appear.

This screen shows the students who will not receive an employer copy of the certificate.
If you want to send these students a student copy instead. There is a toggle labeled 'Send Student Copies'.
If this toggle is active then the students in this list will receive a student copy.
If the toggle is inactive then no certificate will be sent to the students in the table.

Once you have chosen to send or not send student copies to the students who have not granted employer permission, select 'Next'

The utility will now present you will a list of the students that will be delivered their Interim Certificates.
There will be two lists, one for students receiving just the student copy and another for students receiving the employer copy.
If a list has no values, it will not appear, so do not worry if you only see one list.

Once you have confirmed that these lists are correct, select 'Next'.

The utility will then queue the certificates for generation and delivery. Once delivered a copy of the student's certificate will be attached to their Attendee record.