When I try to restart my Mac in Windows 10 Partition it says "Unable to boot"

You need to restart the Mac into Recovery Mode using Command + R so you can launch the Startup Security Utility to modify the security settings of the T2 Mac to allow booting from USB.

About Startup Security Utility on a Mac with the Apple T2 Security Chip - Apple Support

In the future please rotate your images when posting. You can easily do this on your iPhone or iPad by using the instructions in this article.....I would imagine an Android device would have something similar:

https://www.iphonelife.com/blog/5/tip-day-how-rotate-photo

FYI, you have about 10 - 15 minutes after submitting a post to edit that post by clicking the pencil icon located just below your post on the right side.

Which above screen...there are two?

Can you boot into Recovery Mode using Command + R to reach the installer's utility screen? If not, then what happens and what do you see?

You can try booting into Internet Recovery Mode using Command + Option + R instead to see if that makes any difference.

I'm assuming you have a 2018-2020 Intel Mac with the T2 security chip. If so and you cannot access recovery mode, then you can try a DFU firmware Revive, but if that does not help, then you will need to do the more drastic DFU firmware Restore which will also erase the internal SSD (destroying all data on the internal SSD) & prepares it for a fresh installation of macOS which will need to be performed by booting into Internet Recovery Mode.

How to revive or restore Mac firmware - Apple Support

If you can still boot to the internal macOS volume, then I highly recommend you make a backup if you have not already done so.

Edit: Also, please do not type in all CAPS as it is considered shouting & rude, plus it is very difficult to read. Thanks.