Note for Better results:
Does not support multiple displays with M1 MacBook.
Macbook Air/Pro launched between 2016-2018 will support one monitor at a resolution of 4K@60hz and second monitor at 4k@30Hz
Only Intel processor equipped Macbook Air/Pro launched between 2019-2020 will support 4K@60hz on dual monitor.
Some* latest Intel based Macbook Air/Pro models running on macOS Big Sur, may not support 4K resolution.