Cosmetically, it will keep it looking newer if you cover it.
Functionally, should be no problem to park it outdoors. These scoots are likely designed in Taiwan and used throughout Asia - where the sun shines hot, and typhoons are a regular occurence in the summer.
To be more specific, while in Taiwan, I kept my scoot outdoors and it lasted around 6 years before the plastics started to fade. Functionally it ran without issue for over 15 years until I traded it in for a more powerful scoot.
If you do decide to get a cover, don't get the cheap plastic types. Get one is heat-resistant or at least has heat-resistant panels for the exhaust.
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