We provides you with complete custom solution for you to enable terms of services text for the signup page. There are following steps you can follow to Add Terms Text and then enable terms of services text for the sign up page.
You need to first login to your admin control dashboard and click on Setup.
And then Click at settings and Click the button says "Manage terms and Services Text"
For this Page you can type your Agreement terms and Conditions and click update.
Then go back to setup and settings, scroll down and click "view advanced settings" link and check the box where it says "Require Terms and Services Acceptance"