How to use a!iconIndicator in a gridColumn(), the icon cannot display

a!gridColumn( 
label: "Status", 
sortField: "status",
value: if (
fv!row.isTesting, 
    a!iconIndicator( icon: "STATUS_NOTDONE",
    ), 
    a!iconIndicator( icon: "STATUS_OK", 
    ), 
)

  Discussion posts and replies are publicly visible