Can you use assets in doodle mode?

Hi im broke so i recently downloaded csp but im only using the doodle mode that is free, ive never used cso before, but i really wanted to use some assets i have downloaded with my account from the assets store. My only problem now is i have no idea how to actually get the assets into my canvas. Is it even possible? Or can assets only be used in paid modes?

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Thanks in advance if anyone can help .