How install the PHP Pecl Trader extension, on window

I try to install the PHP Pecl Trader extension, as show in this stackoveflow answer https://stackoverflow.com/questions/48685310/how-to-install-php-trader-php-ext-in-windows-10-with-xampp I enter xampp/php and open terminal and run

pear install trader 

this error happen

Notice: Trying to access array offset on value of type bool in r\PEAR\REST.php on line 186
PHP Notice:  Trying to access array offset on value of type bool in C:\xampp\php\pear\PEAR\REST.php on line 186

Notice: Trying to access array offset on value of type bool in C:\xampp\php\pear\PEAR\REST.php on line 186
No releases available for package "pear.php.net/trader" - package pecl/trader can be installed with "pecl install trader"
install failed

how can I install it