If you are testing Chargent's Payment Request feature in a Salesforce Sandbox, but the emails are not being received when you send tests clicking on the "Pay Request" button, you may need to enable outbound email in the Salesforce sandbox.
By default, outbound email in sandboxes is disabled so you don't accidentally email customers or leads.
Setup > Email Administration > Deliverability > Access Level
Most likely it is set to ?No Access? or ?System Email Only? and will need to be changed to ?All Email?