How do you Import PFX file using iControl with Powershell?

There was mention in one of the posts that indicated that the certificate had to on the F5 device before these commands would work. I have looked for info on how to get the cert up to the LTM, but haven't found it. I have yet to find a way to import certificates via PowerShell. These questions have been asked for a few years and it doesn't appear F5 is doing anything to help resolve them. Good luck!