In vendor\square\square\src\SquareClient.php on line 290 to 306 does the function look like:
/**
* Get the base uri for a given server in the current environment
*
* @param string $server Server name
*
* @return string Base URI
*/
public function getBaseUri(string $server = Server::DEFAULT_): string
{
return ApiHelper::appendUrlWithTemplateParameters(
static::ENVIRONMENT_MAP[$this->environment][$server],
[
'custom_url' => $this->customUrl,
],
false
);
}