I exile an Adventure card with the ability of Vivien, Champion of the Wilds.

Vivien say “you may cast it if it's a creature card”

Can I cast the card as an Aventure ?

Someone told me that currently didn't work on MTG Arena but it remind me the interaction between Torrential Gearhulk and Commit // Memory where you could cast Memory with the Gearhulk

No, you may not:

Originally posted by Throne of Eldraine release notes:

For example, if Giant Killer is exiled with the last ability of Vivien, Champion of the Wilds, you can't cast it as Chop Down.

d:^D