The alternating batwing row is great for overall back strength. It targets a variety of back muscles at the same time. I recommend using an incline bench, alternating rows with dumbbells in each hand. The classic spinal erector exercises are deadlifts and front squats. You can do dumbbell Romanian deadlifts, https://dumbbellsetandrack25666.getblogs.net/63126319/details-fiction-and-back-exercises-with-dumbbells