As a general rule for NoMachine keyboard, the client layout must be the same of server layout or the keyboard symbols will be not matched.

Usually Android devices report the system language as keyboard language, regardless of what keyboard language is set on the device.

In order to have the proper keyboard layout in the NoMachine virtual keyboard, it's therefore necessary to set the language in system settings. 

For example to change it on Android 10, Huawei p 2019:

Settings -> System&updates -> Language & input -> Language and region -> English

and set the input language:

Settings ->System&updates -> Language & input -> gboard -> languages -> English

If you have added more than one input language, you can select it from a list when using the keyboard.