Hello Nguyen, welcome to the world of Qlik. I know you will find it exciting.
Currently, no you cannot, Qlik Sense Cloud does not support extensions or images at the moment. You can request a trial of Qlik Sense Enterprise server though. You can contact our concierge service at Contact Qlik Qoncierge Service | Qlik - who can help and work with you.
Also check out these resources:
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