Currently, according to the configuration composer installs the most recent release of Guzzle, precisely from 7.3 branch. P.sh PHP client won't work with this release due to the usage of \GuzzleHttp\Psr7\uri_for function that has been deprecated for some time and has been removed in Guzzle 7.2.
The solution is either to stop using that function or at least adjust the composer config to install Guzzle from 7.1 branch. I tested it with guzzlehttp/guzzle 7.1.1 and it works.
Currently, according to the configuration composer installs the most recent release of Guzzle, precisely from
7.3branch. P.sh PHP client won't work with this release due to the usage of\GuzzleHttp\Psr7\uri_forfunction that has been deprecated for some time and has been removed in Guzzle7.2.The solution is either to stop using that function or at least adjust the composer config to install Guzzle from
7.1branch. I tested it withguzzlehttp/guzzle7.1.1and it works.