Installing the extension on Magento lower than 188.8.131.52¶
Amazon Pay extension doesn’t work out of the box with Magento lower than 184.108.40.206 because of the unsupported version of phpseclib that comes with those Magento versions. However, it is possible to upgrade phpseclib and start using Amazon Pay extension. To do so, please follow the steps:
Identify your Magento version (it’s visible in the footer in Magento admin panel).
Check which security patches you have installed in your Magento shop by running the following command in the root directory of your Magento installation:
Go to Magento 1.x Patches page, find your Magento version and compare the patches which are installed in your Magento shop with the ones required for your version.
Install all missing required patches, next download and install PHP 7 compatibility patch.
Now your Magento is ready to use Amazon Pay extension. Go to Installation section and install the extension.