The secret name for the tls cert isn't configurable, it is common to already have a TLS cert in the deployed namespace, and it might not have the name that the chart assumes (especially if it is a wildcard cert).
Proposal:
use ingress.secretName as the secret value, and if that isn't supplied then use the current value.
https://github.com/invoiceninja/dockerfiles/blob/e5debf03d415a1d1453787e073a1223d6cc4c066/charts/invoiceninja/templates/ingress.yaml#LL57C1-L57C65
The secret name for the tls cert isn't configurable, it is common to already have a TLS cert in the deployed namespace, and it might not have the name that the chart assumes (especially if it is a wildcard cert).
Proposal:
ingress.secretNameas the secret value, and if that isn't supplied then use the current value.