So you could do this with 2 applets on IFTTT with a Glitch app between them to get the data you need from Todoist.
The 1st applet would be a button widget, which sends a webhook request to your Glitch app. You could adapt this Glitch project https://glitch.com/~multi-ifttt-triggers to capture that webhook request, get the list of items in a Todoist project, and then fire off its own webhook back to IFTTT.
The 2nd applet would be a webhook request being received, causing Memobird to print a note with the contents of the webhook (your shopping list).
It looks like there’s a NPM package which will help you work with the Todoist API in Node on Glitch: https://www.npmjs.com/package/node-todoist