Hello,
You may want to hold on to your application for a certified marriage record from Iowa & submit it after signing the application "in front of a notary public."

See the last line of the 2nd paragraph in this item regarding the signature on the application form
(copy & paste the link in your browser):

https://www.idph.state.ia.us/apl/common/pdf/vital_records/ma...

Hope this helps.

Good luck to you!
Nancy