With Foundations Small you can use Up to 3 URLs with up to 2 Keywords/Keyphrases per URL.
HOTH Foundations Medium & Large we accept the exact same inputs -
Up to 3 URLs with up to 5 Keywords/Keyphrases per URL.
You are not required to use all of them. As a rule of thumb, we encourage you to use all 3 URLs and not waste Keyword slots that you don't need to. Don't have 3 URLs? No worries. Many SEOs only submit 1 URL at a time with great success.
NOTE: All URLs and Keywords for any order must be in the same niche.