https://docs.uniswap.org/sdk/v3/guides/swaps/routing
I tried following the instructions and it didn't work.
I realized this github link: "We can get the V3_SWAP_ROUTER_ADDRESS for our chain from GitHub" does not contain the address for SWAP_ROUTER_02 (0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45).
Since I'm a beginner, I assumed the SwapRouter (0xE592427A0AEce92De3Edee1F18E0157C05861564) contract was the one to use. That's a reasonable assumption imo, why else would the docs link to it?
I only realized the error after checking the code here, which contains the correct address for V3_SWAP_ROUTER_ADDRESS : "You can find the full code in routing.ts."
Once I used the correct address, I was able to execute a swap.
Please fix for posterity, I spent a whole day banging my head against the wall trying to figure out why it wasn't working.