How to handle changes on import ? Specially the terraform only attributes [Custom provider]

I have a schema attribute like this :

		Schema: map[string]*schema.Schema{

			"safe_delete": {
				Type:        schema.TypeString,
				Optional:    true,
				Description: "safely delete the resource",
				Default:    true,

basically this attribute comes into picture during destroy and the backing api/sdk doesn’t have this attribute.

On importing this, the value is null if its absent in the configuration and on next plan it is showing a change from null → true and I am getting this

cus_server: Refreshing state... [id=xxx-x-xxxxx-x]

Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
  ~ update in-place

Terraform will perform the following actions:

  # cus_server will be updated in-place
  ~ resource "cus_server" "ser1" {
        id                          = "xxx-x-xxxxx-x"
        name                   = "test-1"
      + safe_delete        = true
        # (18 unchanged attributes hidden)

        # (3 unchanged blocks hidden)

Plan: 0 to add, 1 to change, 0 to destroy.