There are just few steps to set "Accept Special Instruction(s)" for your store.
Login to your Yamimeal Merchent Portal via https://merchant.yamimeal.com/web/merch/#/login
Click on “Merchant Settings” and select “General”
Scroll down and click on "Business Settings"
Scroll down to "Accept Special Instruction(s)" section
Confirm your choice and click "Submit"
If you need further assistance for this request, please send a ticket to Yamimeal customer care representatives via https://help.yamimeal.com/support/. We will try our best to help you as soon as possible.