Calculate fees with Blocktrail/btc.com SDK First of all hi and thanks for your support and your time.

I want to calculate the fees of a blocktrail transaction with blocktrail SDK, before making the transaction, in order to let the recipient pay fees.

Here is what I tried:

$FEES = $wallet-&gt;coinSelection(\Blocktrail\SDK\Wallet::normalizeOutputsStruct(['66f4dec6ab29cd056ce1814c6fdfee05e1524b36' =&gt;'100000']),false,false,\Blocktrail\SDK\Wallet::FEE_STRATEGY_LOW_PRIORITY;
echo "$FEES";
$fee = $FEES['fee'];
echo "$fee";


But this don't work, it says this: Fatal error: Uncaught Blocktrail\SDK\Exceptions\BlocktrailSDKException: Address not recognized how can I fix this error? Thanks for read, hope that you'll have a nice day :)
I am not sure as have not used their api system but it could be down to the format of your bitcoin address you are passing in.

66f4dec6ab29cd056ce1814c6fdfee05e1524b36 is read as a valid bitcoin address using this service

However when I search that address under a block explorer I get the following address which starts with the more common 1 1APPGSyMsPaBUAHtjEm6tPqV9U54JRzmd6

66f is not a start of a bitcoin address i recognise, though there are many out but no mention on the wiki

Thus I would suggest trying your code with the more common bitcoin address format

$FEES = $wallet-&gt;coinSelection(\Blocktrail\SDK\Wallet::normalizeOutputsStruct(['1APPGSyMsPaBUAHtjEm6tPqV9U54JRzmd6' =&gt;'100000']),false,false,\Blocktrail\SDK\Wallet::FEE_STRATEGY_LOW_PRIORITY['fee'];
echo "$FEES";


And see if that works