Hello! My name is Mustafa,
I am hopeful that I will be able to help you find a satisfactory solution.
Unfortunately, this is not a feature that you can choose from the settings. But you can flip the picture after you take the shot.
Open the picture from file explorer, click on the edit button on top, then click on flip image horizontally at the bottom right corner, this will flip your pictures.
To get the option to reverse your image automatically before taking the picture or after taking the picture I would suggest submitting feedback to the support engineering team of Microsoft so that they can add this in future releases.
https://feedbackportal.microsoft.com/feedback
Please let me know if this doesn't work or if you need further assistance.
Note: This is a user-to-user support forum and I am a fellow user.
Warm Regards,
Mustafa