Finally figured it out.
I can buy SURGE on Base using LeoDex with my Keystore wallet and have the token be sent to my Metamask address!
Turns out there's a cool little feature here, when you click on "options" it gives you a choice to "send" to a different address. And that's how I was able to put liquidity in the USDC/SURGE LP (click here if you want to add liquidity too):
