Here's an idea for you!

https://www.hometalk.com/1640828/upcycle-indoor-love-seat-to-outdoor-couch

Upcycle Indoor Love Seat to Outdoor Couch

You could cover with pretty shower curtains for a quick and easy solution.

You can recover it with Sunbrella fabric. It is fade resistant and waterproof

This may not be the best choice... Besides the fabric needing to be outdoor fabric, the actual stuffing material would need to be changed so that it wouldn't absorb moisture and not dry... Then you have the wood frame that isn't the right kind of wood nor treated for outdoors... I'm all about repurposing, but some things just aren't good choices for every purpose.

Diane: Hmmm... I don't know if that is a wise decision... lots of "critters" can get into it! ...even if you cover with Sunbrella fabric.

I don't think that is possible. Maybe get a wooden bench instead.

Hi Diane. For what it would cost you to convert your sofa, you could buy a new outdoor sofa. Good luck Diane. Stay well and healthy.

Hi! The biggest problem you are going to have is that none of the components that make up the couch are intended for outdoors. The upholstery, the frame, is going to fall apart after getting wet, and probably get moldy. Sorry not to be more helpful! Stay safe!

Hi Diane,

Recover it in a good Shower curtain fabric if you are not able to do any better!