Get Invoice details by order id programmatically Magento 2.

You can get the invoice data for the specific order by order id in Magento 2.

Using Magento\Sales\Api\InvoiceRepositoryInterface interface, you need to use getList() function to fetch no. of invoice by sales order id.

Using SearchCriteriaBuilder Class, You need to filter by order id and pass search criteria object to getList() method of InvoiceRepositoryInterface.