As you know this system is in Magento Ecommerce, The Magento2 Ecommerce has a few system requirements.
You will need to make sure your server meets the following requirements: Check All System Requirements here. Check Requirement Here
Please Follow the steps :
php bin/magento setup:upgrade
php bin/magento setup:static-content:deploy -f
php bin/magento cache:flush
Minimum Working days needed for delivery of an order: How many minimum working days are needed to be delivered an order.
Weekends Days or (dayoffs in a week): days off in a week (weekends) (days in which orders can't deliver).
Yearly Holidays (festival and office holidays ): festival and office holidays (days in which orders can't deliver).
Working Hours: Orders can deliver on selected time slots only.