There are 3 ways to use it:
You can purchase a Mega Creator plan which lets you use 100 assets (icons, photos, and illustrations) monthly, add them to your projects and download them in SVG, PNG, or PSD. Reused assets won't get deducted from your asset pool.
Another option is to purchase the Graphics+Music plan, or any other one depending on the assets you need (icons, photos, illustrations) and download needed assets from the website, then upload them to Mega Creator manually for further usage.
Since they were purchased within your paid license, you won't be charged for anything uploaded to Mega Creator manually, but your choice will be limited by the number of assets available in your current account.
You can also download a finished project in high-quality by making a one-time purchase. The cost depends on the number of assets taken from the inbuilt library.
❗️Please note that if the subscription is canceled, the unused credits expire at the end of the paid period.