To install Magisk and gain root in your honor view 10 you have to unlock your bootloader first.
##Please backup your data before proceeding with the process. You will loose all your data if you unlock the bootloader. ##
Please follow below steps to unlock bootloader
1) Create a Huawei ID on this page https://goo.gl/GkkdxE if you don’t have one already.
2) After creating a Huawei id, fill out the details.
3) You will need your phone’s IMEI number, to know that dial * # * # 1357946 # * # * on the dialer app. Fill the required fields and click the Submit button.
4) Save the unlock code you received.
5) Now connect your Honor View 10 to the PC with a USB cable.
6) In the ADB command window, type the following command to boot your Honor View 10 into fastboot mode.
adb reboot bootloader
7) To unlock the bootloader, type the following command and hit Enter. Replace key with the unlock key you’ve previously saved. For example, fastboot oem unlock 44801904392841
fastboot oem unlock [unlock key]