Sorry, I think options like Firefly III for that might not be sufficient for small business, but it was the only great Foss personal finance software for a long time.

Odoo is the gold standard for business. I think they also have a business finance app? It isn't free, but the cost is reasonable.

Otherwise, I use Leantime for project management. If you work in a project-based or contract-based company (like consultancy or design house), then it has a lot of project & product features including time tracking with a plugin. Not financial though.