For anyone getting this error only in Kubernetes (but not locally), you need to add this annotation in the metadata field of the ingress resource:
nginx.ingress.kubernetes.io/proxy-body-size: "0"
"0" means no limit, but you can also specify a fixed limit. Full example:
---apiVersion: networking.k8s.io/v1kind: Ingressmetadata: name: my-ingress annotations: nginx.ingress.kubernetes.io/proxy-body-size: "100m"