issue with php version when install extension

[ADovgiy]

When trying to install extension with composer
composer require onmotion/yii2-survey
getting error

Using version ^0.1.0 for onmotion/yii2-survey
./composer.json has been updated
The "extra.asset-installer-paths" option is deprecated, use the "config.fxp-asse
t.installer-paths" option
Loading composer repositories with package information
Updating dependencies (including require-dev)

Your requirements could not be resolved to an installable set of packages.

Problem 1
- myclabs/deep-copy 1.8.1 requires php ^7.1 -> your PHP version (5.6.31) doe
s not satisfy that requirement.
- myclabs/deep-copy 1.8.1 requires php ^7.1 -> your PHP version (5.6.31) doe
s not satisfy that requirement.
- Installation request for myclabs/deep-copy (locked at 1.8.1) -> satisfiabl
e by myclabs/deep-copy[1.8.1].

Installation failed, reverting ./composer.json to its original content.

[CyberPunkCodes]

5.6 is dead and no longer supported by PHP themselves.

You should be on 7.3 but 7.2 is acceptable. Even 7.1 is only getting security updates now. Reference: PHP.net Supported Versions

Aside from that, it isn't his repo giving the error, it is myclabs/deep-copy, and they require 7.1.

Solution: Upgrade your PHP version. This isn't the only repo/library your going to be having issues with if you don't.