Integrate my CRM with my local invoice provider

I currently have a local billing provider, Alegra, that I would like to connect or integrate with my CRM. It is well-known in the market; however, I want to ensure that the person intervening on the site truly understands its functionalities and can delve into the API required to connect with my local billing provider. At the moment, I am unsure about how to proceed. I believe my local billing provider has an API, and it might be in the cloud. Below, I provide you with the registration link so you can learn about the CRM and let me know if integration is possible: https://affiliatepartner-freshsales.freshworks.com/kyde4dduiqjp