Hi @JcRallyUp, welcome to the Community! 
I did some digging and found a report of that error being caused by a mismatch between the email in the Reply-To E-Mail field in the Zap and the reply-to address set in their Trustpilot account.
Can you take a look at the invitation settings in your Trustpilot account (under Settings > Invitation settings > Email settings) and ensure that they both match.
Keep us posted on how you get on, want to make sure this gets sorted!
Thank you very much! That seemed to be it. Regarding the other question I had about the Custom Action, is there a way to make the Trustpilot API call to invitations-api.trustpilot.com since I’d love to be able to use the Generate service review invitation link endpoint?
You are most welcome @JcRallyUp, glad that sorted it! 
If it isn’t using the right API endpoint it should be possible to change the API endpoint in the custom action’s code under the Advanced tab:
Can you try editing the endpoint in the code for the custom action? Or is copilot not generating the action at all due to that “Due to a domain restriction in Zapier...” error?
Hi @SamB, thanks for looking into this. Here’s what the code generated with Copilot looks like for the URL along with the message provided when I test the action.
This post has been edited by a moderator to include image directly within the post instead.
Thanks for sharing that @JcRallyUp. Hmm, looks like that domain restriction is being enforced on our end which is odd since presumably the Create Invitation action would use the same invitations-api.trustpilot.com domain. 
That said, I found we’ve got a feature request open to be able to generate review links, so I’ve added your vote to that. Can’t make any promises around when it might get added but you’ll definitely get an email from us as soon as it is.
In the meantime, you could try using a Webhooks by Zapier action to generate the review link, as that shouldn’t have the same domain restriction in place. Check out our Send webhooks in Zaps to learn more about how to set it up.
Let us know how you get on with that, happy to lend a hand if you get stuck at all.
@SamB Thanks for this, I’ll see if using the Webhooks is something we can configure to generate these Trustpilot links.
We did speak to a Trustpilot rep who seems to believe the workflow automation for Zapier wouldn’t be applicable overall, as they said “TrustPilot API requires authentication on a weekly basis”. This is just some information the marketing team brought back, my assumption is that the Trustpilot rep was talking about OAuth access information and I believed that Zapier would refresh the Oauth codes and tokens automatically when they expire. Just wanted to confirm that, thanks!
Great question @JcRallyUp! The Webhooks app is great for requests that use basic authentication, but it doesn’t support more advanced methods like OAuth. If OAuth is needed then you might be able to get around it by using a Sub-Zap to get the necessary access token:
Hope that helps. Keep us in the loop on how it goes! 
Thanks @SamB ~
Sorry if this is a basic question - Does the base Create invitation action in the Zap automatically refresh the access token information? https://share.zight.com/GGuj8Qmq
Not a basic question at all @JcRallyUp! The Create Invitation (Trustpilot) action would refresh its own access tokens automatically as the Trustpilot app integration uses OAuth to authenticate. And the same would go for the Custom Action as that would use the credentials of the connected Trustpilot account to authenticate the request being made using OAuth as well.
The Webhooks by Zapier app doesn’t support OAuth but you can potentially have a Sub-Zap use a Webhooks action to fetch and return a fresh Trustpilot authentication token, and then feed it into your Webhooks action in the main Zap.
Let me know if you have any follow-up questions at all. Want to make sure you’ve got all the information you need!
