Output audio to multiple devices in Windows 10

Earlier with the help of stereo mix option it was possible to output the audio to different devices. However the stereo mix option is removed now.

Is there any other way to send audio output to 2 different devices in windows 10?

Try the below steps and check if they helps.

Press Start, type Sound into the search space and select same from the list.
Select Speakers as the default playback device.
Go to the “Recording” tab, right-click and enable “Show Disabled Devices”
A recording device called “Wave Out Mix”, “Mono Mix” or “Stereo Mix” should appear.
Right click on the new device and click “Enable“
Right click on the new device and click “Set as Default Device“
Double click on the new device to open the Properties window
Go to the “Listen” tab
Click on the “Listen to this device” checkbox
Select your HDMI device from the “Playback through this device” list

Now check if you’re able to use the both device at same time.