Use the below steps to display the logo in ABAP ALV header.

    First upload the logo that you want to display in ABAP ALV header.
    Build the ALV header table.
    Pass the TOP-OF-EVENT subroutine name and callback program name to I_CALLBACK_TOP_OF_PAGE and I_CALLBACK_PROGRAM parameters of REUSE_ALV_GRID_DISPLAY function module.
    Display the ALV header and logo by passing the ALV header table built in   step two and logo that you uploaded  in step one to function module ‘REUSE_ALV_COMMENTARY_WRITE’ inside TOP-OF-EVENT subroutine.

TYPE-POOLS: slis.
*----------------------------------------------------------------------*
*     Data Decalaration
*----------------------------------------------------------------------*
DATA: it_spfli TYPE TABLE OF spfli.
DATA: g_repid TYPE sy-repid.
DATA: it_listheader TYPE slis_t_listheader,
      wa_listheader TYPE slis_listheader.
*----------------------------------------------------------------------*
*     START-OF-SELECTION
*----------------------------------------------------------------------*
START-OF-SELECTION.
  g_repid = sy-repid.

  SELECT * FROM spfli INTO TABLE it_spfli.

  PERFORM build_alv_header.

  CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
    EXPORTING
      i_callback_program     = g_repid
      i_callback_top_of_page = 'TOP_OF_PAGE'
      i_structure_name       = 'SPFLI'
    TABLES
      t_outtab               = it_spfli.

*&---------------------------------------------------------------------*
*&      Form  BUILD_ALV_HEADER
*&---------------------------------------------------------------------*
FORM build_alv_header .

*  Type H is used to display headers i.e. big font
  wa_listheader-typ  = 'H'.
  wa_listheader-info ='Flight Details'.
  APPEND wa_listheader TO it_listheader.
  CLEAR wa_listheader.

*  Type S is used to display key and value pairs
  wa_listheader-typ = 'S'.
  wa_listheader-key = 'Date :' .
  CONCATENATE  sy-datum+6(2)
               sy-datum+4(2)
               sy-datum(4)
               INTO wa_listheader-info
               SEPARATED BY '/'.
  APPEND wa_listheader TO it_listheader.
  CLEAR wa_listheader.

*  Type A is used to display italic font
  wa_listheader-typ = 'A'.
  wa_listheader-key = 'Date    :' .
  wa_listheader-info ='SAP ALV Report'.
  APPEND wa_listheader TO it_listheader.
  CLEAR wa_listheader.
ENDFORM.                    " BUILD_ALV_HEADER
*&---------------------------------------------------------------------*
*&      Form  top_of_page
*&---------------------------------------------------------------------*
FORM top_of_page.

  CALL FUNCTION 'REUSE_ALV_COMMENTARY_WRITE'
    EXPORTING
      it_list_commentary = it_listheader
      i_logo         = 'MYLOGO'.

ENDFORM.                    "top_of_page



Serkan AKKAVAK
Computer Engineer
ABAP Developer & SAP S/4 HANA Logistics Consultant
Contact : serkurumsal@yandex.com