Hi,
To begin with, you may want to have a look at these articles:
Solve printing problems on Mac - Apple Support
Add a printer on Mac - Apple Support
However, I guess that you need a printer driver compatible with Big Sur.
Information at https://www.epson.eu/viewcon/corporatesite/kb/index/1018:
"Compatibility details for Epson SX235W
Your product is macOS Big Sur compatible. The product driver is available via the Epson support website.
Printer Driver: Please use v10.85 or later.
Apple Image Capture Application (ICA): Yes. Click here for support on using Image Capture with your scanner."
The problem is that a v10.85 driver is not yet offered for download via the SW235W support page. Some other printers have received updates. So, one approach, used by others while waiting for a file for their own printers, has been to search for a v10.85 driver via another (similar or not) model's web page. This should be looked upon as an experiment; it may or may not work with your printer. See, for example, the various messages under the discussion problema con la stampante Epson WF-2510 - Apple Community (if necessary, you could perhaps try a web translation service such as Google Translate).