Connect any two Bluetooth speakers to iPad Pro simultaneously

I would like to connect two Bluetooth speakers to iPad Pro to play music simultaneously (iPad Pro (12.9-inch) (4th generation) – iPadOS 14.4.2). Playing in sync is advantage but not required as speakers are planned to be in different rooms. I have found some solutions (examples) being able to play music on two devices at the same time – but my understanding is it is strictly limited to AirPods or a Beats headphones.

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I am able to connect two / multiple speakers to iPad Pro at the same time, but not able to select them both at the same time to play music. Also I would not mind if at least I could play music at the same time on iPad speakers and only one Bluetooth speaker. As this way I could still cover two rooms. Is there any solution to this?