AdWords Dynamic Conversion Value Tracking

I am trying to set up AdWords Conversion Tracking to pick up the unique value of each purchase.
I have followed this guide https://ecom-support.lightspeedhq.com/hc/en-us/articles/220319828-Adding-the-Google-Adwords-Conversion-code and replaced the conversion-id and label with those from a Conversion I have set up in AdWords, but it doesn't seem to work.
The website is UK based using GBP £ currency. If anyone has any insight in to how to set this up that would be greatly appreciated.
Thanks.