Asking as a newbie: How do Resource Credit works?

For starters, I can't find an article or guide here (Ecency) that's about Resource Credit.

So I have been here just 3 days ago and everything is not that hard anymore, but only for this one thing;

I'm a blogger, publish and mostly writes about cryptocurrencies, NFT and more that really loves to share my contents to everyone.

But here, I can't post easily as there was an error always saying that "Resource Credit is too low" and I need to wait some time.

Just yesterday, my Resource Credit was at 18% and I managed to post, but right now I have 19% RC but I can't publish my 6-minute read article because of the same error.

Any thoughts?
Anyway, good morning.

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