/claimtooland a golden shovel will be added to your inventory. Warning: this command can only be used once, if you lose it, you'll need to craft a new Golden Shovel.
/res select sizeto make the particles appear again to check your build is within the selection. To easily adjust your selection to make your build fit, you can use
/res select shift[amount]while looking in the direction you want to expand(this works with y coords. too).
/res create [name]and your claim will be created, with the cost charged from your on-hand balance.