I am configuring SAML 2.0 as 'Up-parties' in FoxIDs single identity provider. Documentation is clear and there are lots of custom settings, but I need to change default (autogenerated) entityID. That property I have share in EntityDescriptor section in METADATA I am uploading on my identity provider.
Connecting a SAML 2.0 IdP as up-party in FoxIDs. You can configure / change the autogenerated EntityID by clicking Show advanced settings and adding the wanted EntityID value in the Optional custom SP issuer field.