Hello @Cano93225, certainly get the frustrations on not being able to locate a link to upload documents through our website. To better assist you in getting there, please log into usaa.com and follow this path.
1. Click on Initials to populate menu.
2. Select "Documents"
3. Locate and Click on link "Send Documents to USAA"
4. Follow the steps to Upload Documents.
I hope this helps in guiding you to submit your prior proof of insurance to USAA.