Be sure to open SafeSport on a desktop computer on Google Chrome.

If you’re having more issues, read below.
https://ussoccerfederation.my.site.com/lcsupport/s/article/Why-can-t-I-launch-SafeSport

If you’re still stuck after all that, file a ticket with SafeSport directly.
https://safesport.atlassian.net/servicedesk/customer/portal/4/group/9/create/32