To scan documents from your printer to your Chromebook, first open the Scan app. Start by pressing the 🔎 Search key on your keyboard, then type scan. The Scan app should appear in the results near the left of the screen. Click it or press Enter:

After looking for a moment, the app should find your scanner. Set the folder you want to save to by clicking the Scan to dropdown, then clicking Select folder in Files app...

...then select Google Drive on the left. You can also create or choose a folder to store scans in here. Click Open at the bottom right to set the folder. Then, go ahead and click Scan to scan a document, selecting the Save multiple pages option or choosing a different Source (e.g. the feeder on top of the printer or the flatbed underneath) if needed.