All live payment pages should be served over SSL.
During development & testing, you don't need to setup any SSL certs, it's only something you'll need to do when you want to take real payments from users.
Need a hand getting your SSL Cert in place?
Setting up an SSL cert on your server is normally a straight-forward process. If you need a hand getting this setup drop a line into support and we'll be glad to help you get setup.