Here's the info (in Japanese): https://j-mag.org/2020/10/08/yurucamp-57/
From what I can glean through Google Translate...
The multi-part event is called "I'm in Yamanashi on weekends. Yuru Campaign △"
Digital stamp rally modeled around the one in Heya Camp△ involving 5 towns in the Gonan area of Yamanashi prefecture (Ichikawamisato Town, Fujikawa Town, Hayakawa Town, Minobu Town, Nanbu Town) where winners can recieve a variety of limited edition prizes; each town will have a short audio drama
Minobu: Donburi Kaido Planned gourmet event; visit 3 of 12 place to collect stamps
IchikawamisatoTown: get not-for-sale badges when you eat, drink and shop at restaurants and shops
Stamp rally time period: Saturday, November 7, 2020 to Sunday, January 31, 2021
Audio drama available time period: November 7, 2020 (Sat) 10:00 to November 22, 2020 (Sun) All day