AEM Cloud Services provides OAuth 2 based authentication documented here. For OAuth 2 based authentication in AEM 65 check this post. The solution discussed here is a more simple non standard token based authentication....
1) Create an overlay for the tools nav item /apps/cq/core/content/nav/tools/experience-aem/experience-aem-config
2) Create the Token Auth Config page /apps/eaem-simple-token-based-auth/extensions/simple-token-auth/token-config accessed using http://localhost:4502/apps/eaem-simple-token-based-auth/extensions/simple-token-auth/token-config.html/conf/global/settings/dam/experience-aem