Apple's new iOS 15 now makes it easy to FaceTime via the Web with people who use Android or Windows devices. The Apple person can just create and share a Web link with the Android user. From Apple:
1. Open the FaceTime app and tap Create Link.
2. Tap Add Name, type a name for the meeting, then tap OK. This lets others know which call they're joining.
3. Select the person you want to send the link to, or send the link from Messages, Mail, or any other supported apps in the Share menu.
1. If you receive a link to a FaceTime call, open the link.
2. Enter your name, then select Continue. You might need to allow FaceTime to use your microphone and camera.
3. Select Join. Then wait for the call's host to let you in.
4. Select Leave to leave the call.