Translation Bundle just not show the content?

a!richTextDisplayField(
                  value: a!richTextItem(
                    text: {
                      a!richTextIcon(icon: "camera"),
                      " " & ri!translationBundle["uploadpictures"]
                    },
                    link: a!startProcessLink(
                      processModel: cons!LDA_PM_UPLOAD_PICUTURE_MYASSIGNMENT_SCREEN,
                      processParameters: {
                        buttonAction: null,
                        dispatcherAction: null,
                        driverUsername: null,
                        notifyDispatcher: null,
                        tmsLoadId: null,
                        tripAssignmentDetailsId: index(
                          ri!tripAssignmentDetails,
                          "tripAssignmentDetailsId",
                          {}
                        ),
                        uploadPictureMyassignment: null
                      }
                    )
                  )
                )

Hi can someone tell me the reason why ri!translationBundle["uploadpictures"] not show any string on interface?

As I check the ri!translationBundle, the uploadpictures are setting correctly.

Thanks