While installing Kubuntu, boot/EFI is been allocated windows EFI partition rather than the partition I created on different disk

Question

I installed Kubuntu on my other harddrive. It was working fine but as soon as I check me file system using 'df', it showed all the files are in their respective partion in other harddrive but boot/EFI is in main drive with windows. Even though I created seperate EFI partition, it automatically selects windows EFI while installing. Screenshot of installation. Kubuntu Installation https://imgur.com/a/QEhoCFl. Also, what should be the path for Device for boot loader installation? Should it be the EFI partition I created or the harddrive where the EFI partition is created? Also the EFI partition in is ext4 format instead of fat32.