Each veteran or veteran’s beneficiary entitled to payment under this chapter shall make application to the adjutant general upon a form prescribed by the adjutant general. If the veteran is incompetent or the veteran’s beneficiary is incompetent or a minor, application may be made by the guardian of the veteran or beneficiary, and if there is no guardian, the person determined by the adjutant general to have assumed the major responsibility for the care of the veteran or beneficiary and to be a proper person to receive payment for the veteran or beneficiary may make the application. If a veteran is hospitalized in a state, county, or federal institution and no application has been approved by the adjutant general, the person in charge of the institution may make the application with the approval of the adjutant general. For the purposes of this section, the word “minor” does not include the unremarried spouse of a veteran. Each application must be accompanied by a certified copy of honorable discharge or other evidence of honorable and faithful qualifying service. Each application must be subscribed and sworn to by the applicant in the manner prescribed by the adjutant general.