Compass shorts, no good

I from china, my english bad, sorry.
Want feedback some MongoDB Compaas problems.

I have a table with: _id field, c field.
I want add index like: {c:1, _id:1}
But in Compass “Index” menu, I can no find “_id” to add.

But I can add index in MONGOSH OK. And I can use it OK.
My MONGOSH code: db.a.createIndex({‘c’:1,’_id’:1})

It is no good for new user to know how to add index in Compass.
May you help look look, thank you!

“Index” menu picture is here, you can see no “_id” to add:

Very sorry I just know I can “type” a value, not only select.
Seems the problem fixed, sorry again.
However it is good to auto find a value if possible.