Send user a message during plan step in custom provider

Can I send a message to a user during the plan or pre-apply step? I have an account resource that one cannot create nor delete (a SaaS application where customer service needs to create accounts). However, you can update some aspects of an account.

func resourceAccountCreate(ctx context.Context, d *schema.ResourceData, meta interface{}) diag.Diagnostics {
	api := meta.(*myApi.API)

	var diags diag.Diagnostics

	diags = append(diags, diag.Diagnostic{
		Severity: diag.Warning,
		Summary:  "Account created in Terraform state",
		Detail:   "Your account was added to the Terraform state (but you didn't actually create a new account as that is not allowed).",

	account, err := api.GetAccountDetails()
	if err != nil {
		return diag.FromErr(err)

	resourceAccountRead(ctx, d, meta)
	return diags

This is fine, but the message comes after the apply. How can I inform the user of this before they apply a plan? Or perhaps I should force them to import the account? But then how do I handle when there is a delete action?