I don't exactly understand what your mean "without azure". Both Power BI Service(at least Azure AD) or Power BI Embedded(Power BI workspace collection) are azure based.
Regarding getting an accessToken in Power BI Embedded, you can check DashboardController.cs in power-bi-embedded-integrate-report-into-web-app. You can explicitly specify when the token would expire, which means you can create a token never expires and use it anywhere in your javascript, though it is not recommended.
var embedToken = PowerBIToken.CreateReportEmbedToken(this.workspaceCollection, this.workspaceId, report.Id, Convert.ToDateTime("2017-12-31"));