AVOCADO provides an exclusive link for your store in AVOCADO Dashboard. On your website, you can add a link for users to order for same day delivery. All you have to do is create a button for "Same Day Delivery" and link it to the provided link. The link would look something like below:
https://avocado.shopping/#/setstore/4467/stageswest
If you have a shopify site, see step by step guide to add a link below:
11 STEPS
1 The first step is to open Shopify Dashboard. Go to Online Store and click Navigation

2 Next Click Main menu

3 Click Add menu item

4 Click Name

5 Type Same Day Delivery as Name

6 Click Link

7 AVOCADO provides a unique link for your store in your AVOCADO dashboard. If you are having problem locating the link - email us at hello@avocadonext.com. Type your store's AVOCADO Same Day Delivery Link

8 Choose the link

9 Click Add

10 Scroll down and click Save menu

11 And that's it. You're done. Now users can order for same day delivery right from your website.

Here's an interactive tutorial for the visual learners
https://www.iorad.com/player/1551500/How-to-allow-same-day-delivery-right-from-your-website