The resource credits allow us to do things in the blogchain. Things like voting, commenting and posting. The resource credit is refiling on its own, but if you have more HP - Hive Power you can do more things. It is possible that 3speak needs more RC (resource credits) than you have at the moment. I saw that you have some delegations you can try again or you can wait 15 hours and then try again. You also could try https://giftgiver.site/ it is faucet and there is an option for delegation some HP for 7 days