Basically, any dog who passes their hip testing is cleared for LCP. All you have to do is fill out a form and send it to OFA once you have done either preliminary or final hip testing.
There is no fee charged by OFA to send in the form and get the certificate, but it is pretty much irrelevant to send the form if your dog already has cleared hip testing. So you may see it, you may not see it on the OFA website. Hip testing is what you need to look for, not the LCP certification.
Info from OFA:
The same radiographic image can be used to evaluate the presence of both LCP and hip dysplasia. Evidence of LCP would be detected during an OFA hip dysplasia evaluation and would yield abnormal results. A dog over 12 months of age receiving a normal OFA preliminary report or an OFA hip number is therefore also normal for Legg-Calve-Perthes disease and is automatically eligible to obtain an OFA LCP number.