I found the application on Dept of Veterans affairs. It's a 40-1330.
Also, found records at nationalarchives.com
Dear Ms. Bussell,
Thank you for posting your question on History Hub!
Since the personnel records of the individual you are interested in were destroyed in the 1973 fire, proof of service can be provided from other records such as morning reports, payrolls, and military orders. Please resubmit the GSA Standard Form 180 with any additional information and mail it to NARA's National Personnel Records Center (NPRC), (Military Personnel Records), 1 Archives Drive, St. Louis, MO 63138-1002. Or you may apply online at https://www.archives.gov/veterans/military-service-records/. Please state the request is for the purposes of benefits and ask for copies of the final pay voucher as it ought to be in the holdings of the NPRC. In addition, the NPRC can create a Form 13038 for benefits purposes. You may want to search the VA WWI Index online to obtain the service number and add that to the Form 180.
We hope this information is helpful. Best of luck with your research!