You need either the Pro or Premium version of Power BI to have embedded reports, but it's pretty easy to get that in the short term.

1. Go to: powerbi.com
2. Sign in.
3. Click the gear at the upper right.
4. Pick "Manage Personal Storage" from the menu that appears. (I'm serious.)
5. Click "Try Pro for Free"
6. Click "Start Trial"

This will either start a sixty day trial or extend it. Afterward, you may now add reports by clicking on "Workspaces" at the left nav, picking a particular workspace, and then clicking "Create" at the upper right.