If you want to use SPA editor for an end to end delivery of an angular SPA, you need to be on 6.4.2 or above. Reference at [1]
If you want angular for any custom functionality, you can embed it as a clientlibs as use it. Reference pattern is available in ACS-Commons at [2]
[1] - https://docs.adobe.com/content/help/en/experience-manager-64/developing/headless/spas/spa-overview.h...
[2] - /apps/acs-commons/clientlibs/vendor/angularjs