Hi, Cole.
That's a question which belongs to Jira's support forums, IMO. But just for your information, knowing entityid and the assertion consumer endpoint should be enough to construct metadata by yourself. You can take some other's SP metadata, remove SP-related stuff from there, basically leaving only some headers, and put your urls and cert in it. I'm sure you can google for more such guides, if needed. Also note that you may need to know more details, like what attributes to release, type of nameid to use etc.