No bootloader location option for Persistent installation

I am trying to install Manjaro Plasma Persistent and portable on a USB stick. Many Internet guides suggest to choose the path for installing bootloader location as the same as the Persistent USB itself. However, when I try the installation, there is no option to choose the bootloader location path. I tried all the options such as Replacing a partition, complete format etc. But this option is not available. I am afraid if I proceed without specifying the bootloader location, it will break my existing system.
Please advise how to chose the correct path for bootloader location as USB stick itself.

There is no option for making USB installs in Calamares.

Your only option to get it right is a manual installation. Albeit not being about KDE and including encryption - the following topic covers how to install Manjaro to USB

To answer your question directly could be bad if the context is different and you are the only one knowing the exact setup.

The above guide contains information on bootloader and what to change. Scroll down to Install grub.

Also take the time to check the USB specific consideration section

Thank you for the reply. However, if Calamares cannot directly install it, it’s not an optimal solution for me. In that case, I would prefer another solution.

Actually, I want to install only updatable Manjaro on USB. It need not be portable since the USB will always be connected to my system only.

I already have a UEFI Manjaro installation on my old HDD along with the Grub 2 and bootloader. However, since the HDD is old, it runs slow.

So I want to install Manjaro on USB WITHOUT Grub or bootloader so that it will run fast. I can utilize Grub 2 of my HDD Manjaro and start the Manjaro installed on USB by updating the already installed grub.

Please advise how to do the installation of Manjaro on USB without installing GRUB or Bootloader.