You need to go into BIOS to change (disable / enable) Secure Boot. To do that every time you wish to change OS is a bit onerous. Somehow you will need to get the password to do this. I suggest you make your lesser used system a Virtual Machine and your most used system the Host system. Use VMware Workstation Pro to do this. This has always worked best for me. I have both VMware and Hyper-V (on a different computer).