ARMember provides facility to view, download and clear log files which are generated by ARMember Plugin.
You can find debug log setting from
ARMember
->General Settings
->Debug Log Settings
So from the Debug Log Settings tab, you can find debug log and check what request is made, what response is coming back and through which payment Gateway OR Opt-ins that you are using in ARMember Plugin OR the process done by the ARMember.
You can enable Payment Gateway Debug Log Settings, Opt-ins Debug Log Settings as well as Cron Debug Log Settings to view, download and clear log files.