Trustpilot Integration (Automatic Feedback Service)

Hello Squarespace,

I am currently finding it difficult processing the integration between Trustpilot and Squarespace. My site is a service based business providing these outside the website through invoices/quotes via email (no checkout page onsite for products/services) so I am wanting to essentially integrate this into the contact form or email directly

e.g.

When clients use the contact form and the service is finished/accepted, they receive an email automatically to give a review on Trustpilot for the service.

I have currently tried to use Zapier but it seems I would have to pay a lot for the API key software on Trustpilot. Sorry I do not have any clue on how this works, if anyone would be so lovely to help me out here I would be forever grateful! 😊

Kind regards,

B