Only the Superintendent of a district or CEO of a charter school will be able to see the "Submit" button at the end of the SSEC form.
If you are not sure who is the CEO of your school, you can visit the SEDREF Query page at: https://portal.nysed.gov/pls/sedrefpublic/SED.sed_inst_qry_vw$.startup
You can search for the school by entering the school name and then "%" sign or you can enter the BEDS code in the box for "SED Code".