Photograph the backyard from the back door or an upstairs window, so the frame includes the house wall and the area where the patio will go. Shoot in soft daylight, avoid strong midday shadows, and step back far enough to include fences or trees that define the edges.
Upload the photo to the AI garden design tool and describe the plan: "keep the house and fence, add a 14 x 16 foot porcelain paver patio, cedar pergola over a dining table for six, string lights, grasses along the edges." The image shows the patio in your real yard and perspective, so you can judge size and placement before you pay for materials.
Generate two or three versions with different surfaces or shade options, such as flagstone versus pavers, or a pergola versus a shade sail. Seeing the options in place helps you agree as a household and gives a landscaper a clear picture of what you want.