In case of failure to satisfactorily settle a charge by conference or conciliation, or in advance thereof if circumstances so warrant, the official may issue a written notice together with a copy of the charge, as the same may have been amended, requiring the person, employer, employment agency, or labor organization named in the charge, hereafter referred to as respondent, to answer the charge in writing within ten days after the date of the notice or within extended time the investigating official may allow.
SDCL 20-13-34