API access for generating and downloading "Attestations Fiscales" (Service à la Personne)

I am building a SaaS product for a client that does "service à la personne" and I need to connect to a billing product for billing and attestations fiscales. It would be a big plus if we could download the attestations fiscales through the API. This would allow me to choose Abby as the best billing solution for my client with no doubt. This is the only feature missing.