A managed resource "resource" "inviulrestapi" has not been declared in the root module

Terraform Providers
1

I am trying to create a resource type in my new terraform provider- inviulrestapi. When I am running sample.tf file in my local getting below error on terraform plan.

> $ terraform plan

> Error: Invalid resource type
> on sample.tf line 15, in resource “inviulrestapi” “myFirstRestCall”:
> 15: resource “inviulrestapi” “myFirstRestCall” {

> The provider provider.inviulrestapi does not support resource type
> “inviulrestapi”.

> Error: Reference to undeclared resource

> on sample.tf line 30, in output “myRestCallOutput”:
> 30: value = resource.inviulrestapi.myFirstRestCall.resp_out

> A managed resource “resource” “inviulrestapi” has not been declared in the
> root module.

Source Code: terraform-provider-inviulrestapi/inviulrestapi at avinash-resource · inviul/terraform-provider-inviulrestapi · GitHub

How to resolve this error?

Thanks in advance