1

Get Swap Price

Get a price for a given token pair. Alternatively, call GetSwapPrices to get a list of available options. Make sure that a DEX such as UniSwap has enough funds for your tokens.
2

Get Swap Quote

When you know the price for a given token pair, call Get Swap Quote for the same pair to get the required transaction data for your swap.
3

Send Transaction

Now that you have your transaction data from Get Swap Quote, you construct a transaction object and first add the Approve Data and then the Transaction Data to it. Make sure that the order of calling Add Raw is the same.