We're trying to separate our clients into 3 categories based on the date they were last invoiced (not when a CRM deal has been won).

I've set up a custom field called 'Last Invoice Date' in the Accounts module in CRM. I've also replicated this field in Invoice and FSM, and they're mapped.

I'm trying to update this field based on when an invoice is raised for that specific account, either in FSM or Invoice (they're synced, so it doesn't matter which).

What's the easiest way to achieve this, please?

I've tried using Zoho Flow, but either I can't find the required triggers, or it's not possible to fetch the required fields - hopefully I'm just missing something obvious!