I'm trying to use with Magento 2.3, but I have the following problem:
Problem 1
- magepsycho/magento2-custom-shipping 1.0.2 requires php ~5.5.0|~5.6.0|~7.0.0 -> your PHP version (7.1.3) overridden by "config.platform.php" version (7.1.3) does not satisfy that requirement.
I'm trying to use with Magento 2.3, but I have the following problem: