Here is how you can add delivery slots in shopfront:
Step 1: Click on 'More' on bottom of the main page
Step 2: Click on Shopfront
Step 3: Click on Settings at the bottom of the screen
Step 4: Click on the enable icon beside 'Delivery' and click on the checkbox under it.
Step 5: Click on 'Add new delivery slot'
Step 6: Enter a new delivery slot and click on 'Add new slot'
Step 7: Click on apple changes on upper right corner of the screen
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