The prerequisite for WiiM Mini to be displayed in Amazon music is to sign in to Alexa.
Please follow these steps to improve your problem:
- 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 some minutes, Amazon Music should take some time to fetch a new device.