I dual booted manjaro xfce with a usb stick, I swapped over to it and now I can’t change back to windows 11, there is no option for it in bios and my pc auto boots into manjaro. How do I boot back into windows 11?
I am uncertain by your post if you actually have installed Manjaro or just booted up the live .iso.
Just in case: remove the usb stick and reboot the computer.
Or, if you actually have installed Manjaro check in GRUB (/etc/default/grub)
# Uncomment this option to enable os-prober execution in the grub-mkconfig command
#GRUB_DISABLE_OS_PROBER=false
Uncomment the above line (as root user) and update grub (in terminal: sudo update-grub) and reboot
Welcome to the Forum 
To change bootloader if your UEFI-BIOS automatically boots into one operating system you should use your shortcut of the BIOS to choose which one to boot.
This is most likely F8 right when you power on your device, keep it pressed until the BIOS-POST has finished and it will show you a menu…
Depending on your configuration Grub might not be able to detect other Operating Systems …
To see which boot loaders are configured in your UEFI-BIOS you can use the following command, and also change it with same command see the man page of it:
efibootmgr