How can I change the 'Activity Start Time' in Tcode '/N/SAPAPO/SEQ1' by using BAPI.

I usage a bapi '/SAPAPO/RRP_LC_ORDER_CHANGE' to alteration this 'Activity Start Time', but it does not instrumentality immoderate mistake connection and 'SY_SUBRC = 0'. 'Activity Start Time' person nary immoderate change. Tcode: '/N/SAPAPO/SEQ1' 

Please assistance maine to cheque the pursuing code:

DATA: iv_order      TYPE /sapapo/orderuid,
      gv_simversion TYPE /sapapo/vrsioid,
      gt_ordkey     TYPE /sapapo/om_ordkey_tab,
      gt_order      TYPE /sapapo/om_order_ext_tab,
      gt_activities TYPE /sapapo/om_tab_act,
      gs_ordkey     TYPE /sapapo/ordkey,
      gs_order      TYPE /sapapo/om_order_ext_str.

iv_order = 'kTy6E{AL7k{dc0zXuY8X6G'.
gv_simversion = '000'.

CALL FUNCTION '/SAPAPO/RRP_LC_ORDER_GET_DATA'
  EXPORTING
    iv_order      = iv_order
    iv_simversion = gv_simversion
  IMPORTING
    es_ordkey     = gs_ordkey
    et_ordkey     = gt_ordkey
    es_order      = gs_order
    et_order      = gt_order
    et_activities = gt_activities.
IF sy-subrc = 0.
  DATA: gv_method      TYPE /sapapo/om_method VALUE 'G',
        gv_application TYPE /sapapo/rrp_application VALUE 'I',
        ls_order       TYPE /sapapo/om_order,
        gt_rc          TYPE /sapapo/om_lc_rc_tab.
  DATA: iv_simid       TYPE /sapapo/vrsioid VALUE '000'.

  READ TABLE gt_activities ASSIGNING FIELD-SYMBOL(<fs_activities>)
  WITH KEY resid = '1oXmGQmT7k{9ZuMk6lKX6G'.
  IF sy-subrc = 0.
    <fs_activities>-startti = '20241230003104'.
  ENDIF.

  ls_order =  CORRESPONDING #( gs_order ).

  CALL FUNCTION '/SAPAPO/RRP_LC_ORDER_CHANGE'
    EXPORTING
      iv_method      = gv_method
      is_ordkey      = gs_ordkey
      it_activities  = gt_activities
      iv_application = gv_application
      iv_flush       = abap_true
    IMPORTING
      et_rc          = gt_rc
    EXCEPTIONS
      error_in_opr   = 1
      invalid_params = 2
      unknown_error  = 3
      OTHERS         = 4.
  IF sy-subrc = 0.
    CALL FUNCTION '/SAPAPO/SEQM_RRP_COMMIT'
      EXCEPTIONS
        commit_error = 1
        OTHERS       = 2.

    CALL FUNCTION 'RPM_FCODE_SAVE'
      EXPORTING
        iv_simid    = iv_simid
        iv_popup    = space
        iv_show_msg = space
      EXCEPTIONS
        fatal_error = 1
        other_error = 2
        OTHERS      = 3.

    COMMIT WORK AND WAIT .
    CALL FUNCTION '/SAPAPO/RRP_COMMIT'.
  ENDIF.
ENDIF.