This KB outlines the steps required to update the enroll notification email after you have already deployed the CA API Developer Portal per the steps outlined in our product documentation.
https://techdocs.broadcom.com/us/en/ca-enterprise-software/layer7-api-management/api-developer-portal/5-2/install-configure-and-upgrade/install-portal-on-docker-swarm/install-and-configure-api-portal.html
All supported versions of the API Portal