Go to Sections > Sale popup
Choose collection you wanna upsale
Limit Products: Auto choose 50 products to show
Sequential: It follow by: product1 > product2 > product3 > product4 > ect
Random: It follow by random: product1 > product3 > product8 > product15 > ect
Time between prev product and next product
This section will be setted time unit for start time.
This section will be setted time for stay time.
Separate with '|'. If you not want use list user you can write a text.
Hope you success!!