Implementing SSL/SRTP into FreePBX 13

I’ve been following two guides from the wiki in order to implement SSL/TLS and SRTP into our pbx system. I’ve been following the guide on cert management in order to upload our SSL cert which is from a trusted CA and have been having a bit of trouble even getting that done. We’re currently running 13.0.163 and the guides are somewhat different compared to our system. Rather than being able to select a cert and private key and upload it it only has an option to paste them in. I did this with just the private key by mistake and when trying to delete or edit the cert I get hit with errors and am unable to do either. Any suggestions on how to go about this and what exactly I’d need to provide to get further assistance would be great. Thanks.

Guides from the wiki being used:
PHON/TLS+and+SRTP

FPG/Certificate+Management+User+Guide#CertificateManagementUserGuide-ManagingCertificateAuthority(CA)

I can’t add links being a new user.