Yes, you can. After WiiM Mini is signed into Amazon, you can cast music from Amazon Music App to the WiiM Mini directly.
Please follow these steps:
- Go to Browse->Amazon Alexa to sign in to your Amazon account in the WiiM Home app. Please make sure the account is the same as Amazon Music.
- Go to Now Playing -> Cast to check if WiiM Mini is under `Select a Device to Play Music`.
- If you can see WiiM Mini, please wait for a couple of minutes then Amazon Music should take some time to fetch a new device.
Here's a link to a video for your reference.
If you still can't see your device on Amazon Music app, the issue maybe caused by the different location of the store.