How can I customise this notice? "Keyfield cannot be Blank"

[Sentra_Ventures]

How can I customise this notice? “Keyfield cannot be Blank”

[LeventK]

Try with below expressions in Valid_if and Invalid_value_error properties but not sure if will effect as this is a system message:

--Valid_if--
ISNOTBLANK([_THIS])

--Invalid Value Error--
IFS(
    ISBLANK([_THIS]), "Your_Message_Here"
)