Do you need an itemized list of all the foods bought? Or just the portion of the receipt showing the date and the price paid of items to show proof that you actually bought stuff?
Just because you need a paper receipt doesn't mean you can't print out a digitized photo, or several pieced and pasted together onto one sheet of paper. A single screenshot doesn't need to take up a whole sheet of paper. It can be sized down to, say, 4 or six screenshots on one page of paper, yet still readable. They basically just want to be able to see the dates and amounts clearly.
If you have a Windows computer, when you are on a web page, you can shrink down the fonts to a smaller size by pressing CTRL and the - (dash/minus) buttons at the same time. Do this a couple times to get the size you want. Later to get the font back to the right size, press CTRL and the + (plus sign) buttons at the same time.
Windows 10 also has an app called Snipping (or Snip & Sketch on newer computers,) which make screenshots, This app is different than just the Windows button and PrntScr buttons pressed at the same time as you can also just snip a SECTION of the screen you want. Say, you want to get rid of all the excess Instacart stuff along the borders and only want the middle section, OR you don't want the top 1 inch of each page, you can just size and snip the section you want.
To find Snipping, click on your Windows button in the lower right corner, scroll down to "S" and Snipping or Snip and Sketch should be there. Open the app and look for the "Mode" button to change how you want to snip.
Third, you can also use your photo apps to crop photos to get rid of extraneous stuff around the sections you need.
