You can view them at the following pages:
Received shoutouts:
https://sketch.pixiv.net/lives/histories
Sent shoutouts:
https://sketch.pixiv.net/lives/giftings
You can view them at the following pages:
Received shoutouts:
https://sketch.pixiv.net/lives/histories
Sent shoutouts:
https://sketch.pixiv.net/lives/giftings