Asked to increase tip?

I ordered a couple high dollar items from costco that totaled about $320. I tipped a flat $30 (for reference, when checking out on the Costco app, the highest recommended tip was $29, so I had to click other to do an even $30). I live about a 10 minute drive from Costco. When the instacart shopper delivered the order, she messaged me and said “if you are satisfied with my service please increase your tip.” Should I be tipping a full 20% on a high dollar order, even if it’s not very many items and no heavy or overly large items?

Edit: thank you everyone for your opinion! If you’re curious I ended up not adjusting the tip at all (or replying to their message). I went back and checked and the time the shopper started shopping to drop-off at my door was only 33 minutes….I feel that $30 was generous for such a short amount of time and no heavy items.