Are you using the built-in provider you must disable the feature in the UI at the parent level. All children will be affected.

Read more at https://docs.developers.optimizely.com/content-management-system/docs/optimizely-languages#configure-auto-translation

If you want a more granular approach you'll need to do some coding.

Ive looked at the plugin, and its really half done, not every thing is implemented the right way. I will report that.There is  

"EPiServer": {
    "CmsUI": {
      "LanguageManager": {
        "RestrictedTypes": [
          "AlloySandbox.Models.Pages.*",
          "AlloyTemplates.Models.Pages.ExamplePage2"
        ]
      }
    },

But it is never used in the code! So the way is to override LanguageBranchManager.

You can exlude properties by overriding IEnumerable<string> ExcludedProperties => new string[2] { "CatalogContent.SeoUri", ".MetaTitle" };

But you need to override many methods in the ILanguageBranchManager because it is poorly build. 

Still, i dont see you can disable the button, you can trigger the autotranslate but return false, you get a message "Error see the logs" which is not user friendly. 

Hi Luc Gosso (MVP), Eric Herlitz,

Currently I am overriding ILanguageBranchManager with all methods. I am triggering autotranslation it is return false. Page is not translating throwing warning "Error occurs while translating content, please check the logs for more details." 
As for now i did this implementation. But i was expecting this warning pop up massage also should not come. But i am unable to achieve this.

Thanks,
Deepmala 

Hi Deepmala S, 

Thats the expected behaviour.

https://support.optimizely.com/hc/en-us/articles/33555909069069-Error-occurs-while-translating-content-please-check-the-logs-for-more-details 

If you need to still disabled this popup, you can no-op success(Perform no operation and return success) at service level

Hope this helps.